Description of problem:
-----------------------

Attempt to setup update playbook with custom's stack name fails:

openstack overcloud update stack --init-minor-update \
    --stack qe-cloud \
    --container-registry-file /home/stack/virt/docker-images.yaml 2>&1
...
Waiting for messages on queue '55d27f18-3a8e-470d-8a1c-377000c0fc9b' with no timeout.
{u'execution': {u'created_at': u'2018-02-21 11:52:03',
                u'id': u'bf3cef92-4d6d-4175-90ce-f52354626934',
                u'input': {u'ceph_ansible_playbook': u'/usr/share/ceph-ansible/site-docker.yml.sample',
                           u'config_dir': u'/tmp/',
                           u'container': u'qe-cloud',
                           u'container_registry': {u'parameter_defaults': {u'DockerAodhApiImage': u...
                           u'queue_name': u'55d27f18-3a8e-470d-8a1c-377000c0fc9b',
                           u'skip_deploy_identifier': False,
                           u'timeout': 240},
                u'name': u'tripleo.package_update.v1.package_update_plan',
                u'params': {u'namespace': u''},
                u'spec': {u'description': u'Take a container and perform a package update with possible breakpoints',
                          u'input': [u'container',
                                     u'container_registry',
                                     u'ceph_ansible_playbook',
                                     {u'timeout': 240},
                                     {u'queue_name': u'tripleo'},
                                     {u'skip_deploy_identifier': False},
                                     {u'config_dir': u'/tmp/'}],
                          u'name': u'package_update_plan',
                          u'tags': [u'tripleo-common-managed'],
                          u'tasks': {u'clean_plan': {u'action': u'tripleo.plan.update_plan_environment',
                                                     u'input': {u'container': u'<% $.container %>',
                                                                u'delete': True,
                                                                u'env_key': u'parameter_defaults',
                                                                u'parameter': u'CephAnsiblePlaybook'},
                                                     u'name': u'clean_plan',
                                                     u'on-error': u'set_update_failed',
                                                     u'on-success': u'get_config',
                                                     u'type': u'direct',
                                                     u'version': u'2.0'},
                                     u'get_config': {u'action': u'tripleo.config.get_overcloud_config',
                                                     u'name': u'get_config',
                                                     u'on-error': u'set_update_failed',
                                                     u'on-success': u'send_message',
                                                     u'type': u'direct',
                                                     u'version': u'2.0'},
                                     u'send_message': {u'action': u'zaqar.queue_post',
                                                       u'input': {u'messages': {u'body': {u'payload': {u'execution': u'<% execution() %>',
                                                                                                       u'message': u"<% $.get('message', '') %>",
                                                                                                       u'status': u"<% $.get('status', 'SUCCESS') %>"},
                                                                                          u'type': u'tripleo.package_update.v1.package_update_plan'}},
                                                                  u'queue_name': u'<% $.queue_name %>'},
                                                       u'name': u'send_message',
                                                       u'on-success': [{u'fail': u'<% $.get(\'get_config\') = "FAILED" %>'}],
                                                       u'type': u'direct',
                                                       u'version': u'2.0'},
                                     u'set_update_failed': {u'name': u'set_update_failed',
                                                            u'on-success': u'send_message',
                                                            u'publish': {u'message': u'<% task(update).result %>',
                                                                         u'status': u'FAILED'},
                                                            u'type': u'direct',
                                                            u'version': u'2.0'},
                                     u'update': {u'action': u'tripleo.package_update.update_stack container=<% $.container %> timeout=<% $.timeout %> container_registry=<% $.container_registry %> ceph_ansible_pl
aybook=<% $.ceph_ansible_playbook %>',
                                                 u'input': {u'ceph_ansible_playbook': u'<% $.ceph_ansible_playbook %>',
                                                            u'container': u'<% $.container %>',
                                                            u'container_registry': u'<% $.container_registry %>',
                                                            u'timeout': u'<% $.timeout %>'},
                                                 u'name': u'update',
                                                 u'on-error': u'set_update_failed',
                                                 u'on-success': u'clean_plan',
                                                 u'type': u'direct',
                                                 u'version': u'2.0'},
                                     u'update_plan': {u'action': u'tripleo.plan.update_from_dir',
                                                      u'input': {u'container': u'<% $.container %>'},
                                                      u'name': u'update_plan',
                                                      u'on-error': u'set_update_failed',
                                                      u'on-success': u'update',
                                                      u'type': u'direct',
                                                      u'version': u'2.0'}},
                          u'version': u'2.0'}},
 u'message': None,
 u'status': u'FAILED'}
Started Mistral Workflow tripleo.package_update.v1.package_update_plan. Execution ID: bf3cef92-4d6d-4175-90ce-f52354626934

Problem is that stack is updated, just client terminates.
openstack stack list
+--------------------------------------+------------+----------------------------------+-----------------+----------------------+----------------------+
| ID                                   | Stack Name | Project                          | Stack Status    | Creation Time        | Updated Time         |
+--------------------------------------+------------+----------------------------------+-----------------+----------------------+----------------------+
| df7ce7ad-2d6b-4e80-b4d9-a73a48e65050 | qe-cloud   | 65046383148545c283dc87a5172d29e0 | UPDATE_COMPLETE | 2018-02-21T10:19:08Z | 2018-02-21T11:53:31Z |
+--------------------------------------+------------+----------------------------------+-----------------+----------------------+----------------------+

Version-Release number of selected component (if applicable):
-------------------------------------------------------------
openstack-tripleo-common-7.6.3-10.el7ost.noarch
openstack-mistral-engine-5.2.0-1.el7ost.noarch
python-mistralclient-3.1.3-2.el7ost.noarch
python-mistral-5.2.0-1.el7ost.noarch
puppet-mistral-11.3.0-2.el7ost.noarch
openstack-mistral-api-5.2.0-1.el7ost.noarch
python-mistral-lib-0.3.1-1.el7ost.noarch
openstack-mistral-executor-5.2.0-1.el7ost.noarch
openstack-mistral-common-5.2.0-1.el7ost.noarch

Steps to Reproduce:
-------------------
1. Deploy oc with custom name
2. Update uc
3. Try prepare playbooks for minor update