If user specifies registry a full image name is constructed by
concatenation of the registry, namespace and image. Currently
concatenation does not include '/' if registry is non-empty but
it should. If registry is empty '/' is not required.
This fix covers both use cases with help of Ansible filter.
Change-Id: I0588dd0da55d777e6caa7eb47d51b2435d38d5e0
Closes-Bug: #1479013
2887c6d2e4