Description of problem:
Trigger upgrade against atomic hosts ha, upgrade failed at task [Create the ha systemd unit files].

failed: [x.x.x.x] (item=api) => {
    "failed": true, 
    "item": "api"
}

MSG:

AnsibleUndefinedVariable: 'l_bind_docker_reg_auth' is undefined
failed: [qe-jliu-con1-master-etcd-1.0922-8gh.qe.rhcloud.com] (item=controllers) => {
    "failed": true, 
    "item": "controllers"
}

MSG:

AnsibleUndefinedVariable: 'l_bind_docker_reg_auth' is undefined
	to retry, use: --limit @/usr/share/ansible/openshift-ansible/playbooks/byo/openshift-cluster/upgrades/v3_7/upgrade.retry


Version-Release number of the following components:
atomic-openshift-utils-3.7.0-0.127.0.git.0.b9941e4.el7.noarch

How reproducible:
always

Steps to Reproduce:
1. Install HA env on atomic hosts.
2. Trigger upgrade
# ansible-playbook -i hosts /usr/share/ansible/openshift-ansible/playbooks/byo/openshift-cluster/upgrades/v3_7/upgrade.yml -v|tee log
3.

Actual results:
Upgrade failed.

Expected results:
Upgrade succeed.

Additional info:
Please attach logs from ansible-playbook with the -vvv flag