With 60e7c51df4cf061ebbb435a959ad63c7d3a296bf the behaviour of
`openstack image create` changed so that you can't create an image
with the same name. This patch restores the previous functionality.
Story: 2008229
Task: 41069
Change-Id: Ia0f4920371a918e94d1ccf9fcfcbf90ff885a455