Description of problem:
-----------------------
After FFU upgrade from RHOS-10 to RHOS-13 next tempest test fails:
neutron_tempest_plugin.scenario.test_floatingip.FloatingIPQosTest.test_qos[id-5eb48aea-eaba-4c20-8a6f-7740070a0aa3]:
...
Body: {"server": {"OS-EXT-STS:task_state": "deleting", "addresses": {"tempest-test-network--1421962914": [{"OS-EXT-IPS-MAC:mac_addr": "fa:16:3e:fe:46:b2", "version": 4, "addr": "10.100.0.27", "OS-EXT-IPS:type": "fixed"}, {"OS-EXT-IPS-MAC:mac_addr": "fa:16:3e:fe:46:b2", "version": 4, "addr": "10.0.0.234", "OS-EXT-IPS:type": "floating"}]}, "links": [{"href": "https://[2620:52:0:13b8:5054:ff:fe3e:1]:13774/v2.1/servers/3c1a913f-0763-4cf0-adad-33f0996a6159", "rel": "self"}, {"href": "https://[2620:52:0:13b8:5054:ff:fe3e:1]:13774/servers/3c1a913f-0763-4cf0-adad-33f0996a6159", "rel": "bookmark"}], "image": {"id": "0a876bc3-da11-4acb-a81c-c6e4d3d5f59e", "links": [{"href": "https://[2620:52:0:13b8:5054:ff:fe3e:1]:13774/images/0a876bc3-da11-4acb-a81c-c6e4d3d5f59e", "rel": "bookmark"}]}, "OS-EXT-STS:vm_state": "active", "OS-SRV-USG:launched_at": "2018-09-15T10:06:28.000000", "flavor": {"id": "b723afb8-f2fb-4407-ab04-e20d71643839", "links": [{"href": "https://[2620:52:0:13b8:5054:ff:fe3e:1]:13774/flavors/b723afb8-f2fb-4407-ab04-e20d71643839", "rel": "bookmark"}]}, "id": "3c1a913f-0763-4cf0-adad-33f0996a6159", "user_id": "195fe9398ed44665a81c1e55c3ac78dc", "OS-DCF:diskConfig": "MANUAL", "accessIPv4": "", "accessIPv6": "", "progress": 0, "OS-EXT-STS:power_state": 1, "OS-EXT-AZ:availability_zone": "nova", "config_drive": "", "status": "ACTIVE", "updated": "2018-09-15T10:08:54Z", "hostId": "437054ffaa3b4197ea4ba9ec3d76e84468206ae42fc822fa582ade0c", "OS-SRV-USG:terminated_at": null, "key_name": "tempest-keypair-test-9107797", "name": "tempest-server-test-137000209", "created": "2018-09-15T10:06:19Z", "tenant_id": "ba981e08da3145659e6c7f090d155bc3", "os-extended-volumes:volumes_attached": [], "metadata": {}}}
2018-09-15 06:08:59,010 12879 INFO     [tempest.lib.common.rest_client] Request (FloatingIPQosTest:_run_cleanups): 404 GET https://[2620:52:0:13b8:5054:ff:fe3e:1]:13774/v2.1/servers/3c1a913f-0763-4cf0-adad-33f0996a6159 0.129s
2018-09-15 06:08:59,011 12879 DEBUG    [tempest.lib.common.rest_client] Request - Headers: {'Content-Type': 'application/json', 'Accept': 'application/json', 'X-Auth-Token': '<omitted>'}
        Body: None
    Response - Headers: {'status': '404', u'content-length': '111', 'content-location': 'https://[2620:52:0:13b8:5054:ff:fe3e:1]:13774/v2.1/servers/3c1a913f-0763-4cf0-adad-33f0996a6159', u'x-compute-request-id': 'req-daba7f97-2a36-4285-b84b-e8b724d3902a', u'vary': 'OpenStack-API-Version,X-OpenStack-Nova-API-Version', u'server': 'Apache', u'openstack-api-version': 'compute 2.1', u'connection': 'close', u'x-openstack-nova-api-version': '2.1', u'date': 'Sat, 15 Sep 2018 10:08:58 GMT', u'content-type': 'application/json; charset=UTF-8', u'x-openstack-request-id': 'req-daba7f97-2a36-4285-b84b-e8b724d3902a'}
        Body: {"itemNotFound": {"message": "Instance 3c1a913f-0763-4cf0-adad-33f0996a6159 could not be found.", "code": 404}}
}}}

Traceback (most recent call last):
  File "/usr/lib/python2.7/site-packages/neutron_tempest_plugin/scenario/test_floatingip.py", line 268, in test_qos
    sleep=1)
  File "/usr/lib/python2.7/site-packages/neutron_tempest_plugin/common/utils.py", line 73, in wait_until_true
    raise WaitTimeout("Timed out after %d seconds" % timeout)
neutron_tempest_plugin.common.utils.WaitTimeout: Timed out after 120 seconds

Version-Release number of selected component (if applicable):
-------------------------------------------------------------
openstack-neutron-12.0.3-5.el7ost.noarch
openstack-neutron-bigswitch-agent-12.0.3-0.20180419202353.a59c13d.el7ost.noarch
openstack-neutron-bigswitch-lldpr-12.0.3-0.20180419202353.a59c13d.el7ost.noarch
openstack-neutron-common-12.0.3-5.el7ost.noarch
openstack-neutron-lbaas-12.0.1-0.20180424200349.cdbf25c.el7ost.noarch
openstack-neutron-metering-agent-12.0.3-5.el7ost.noarch
openstack-neutron-ml2-12.0.3-5.el7ost.noarch
openstack-neutron-openvswitch-12.0.3-5.el7ost.noarch
openstack-neutron-sriov-nic-agent.noarch

openstack-tripleo-heat-templates-8.0.4-20.el7ost.noarch

Steps to Reproduce:
-------------------
1. Run test after FFWD upgrade from RHOS-10 to RHOS-13

Additional info:
----------------
Virtual environment: 3controllers + 2computes + 3ceph, uc/oc with ssl, ipv6