Remove version-descovery call for upgrades.
Remove version-descovery call for upgrades.

The tripleo-overcloud role will always call the version-discovery
role at the very beginning of its execution. For that reason, there
is no need to re-run the version-discovery role again during upgrades
as it seems to interfere with the version calculated at the very
begginning and the overcloud nodes do not get set the proper version
from the undercloud.

Change-Id: If243f9b7f2cd1ff5e530df87cce3fc4f91562036

redhat-openstack/infrared,redhat-openstack/infrared,redhat-openstack/infrared