rhel-osp-director: "openstack overcloud update stack --templates  -e <yaml> -i overcloud" is running for a long time although the yum repos aren't avilable.


Environment:
instack-undercloud-2.1.2-23.el7ost.noarch

Steps to reproduce:
1. Deploy an overcloud registered with RHN
openstack overcloud deploy --templates --control-scale 1 --compute-scale 1 --ceph-storage-scale 1 -e <yaml> --ntp-server <IP>  --timeout 90 --compute-flavor compute --control-flavor control --ceph-storage-flavor ceph --rhel-reg --reg-method portal --reg-org <ID>  --reg-activation-key 'key'

2. Attempt to update the stack:
openstack overcloud update stack --templates  -e <yaml> -i overcloud

Note: yum repolist on 2 hosts out of 3 shows an empty list after the update started. The repos were there before attempting the update. 


Result:
The update process doesn't end for a long time, keeps on generating "IN_PROGRESS" lines. 
Manually fixed the repos on the 2 remaining nodes. The update doesn't seem to start on them, although the "IN_PROGRESS" lines are still being generated.
No "yum" process on the nodes.

Expected result:
The update process should end with error due to the missing repos to get the updates from.