
There's a check to make sure that we only run mirroring against interesting branches by filtering out any that aren't HEAD or don't start with remotes/origin, but if we specify a branch on the command line, we want that branch no matter what. This is primarily so we can run mirroring tests on proposed changes to openstack/requirements. Change-Id: I19cd2b032b6219aed972abb95a180e3d402d529e