Fallback to rpm-master when branch is *-rdo
Fallback to rpm-master when branch is *-rdo

The branch fallback code decided a branch was a distgit one only
if it started with rpm-, and it was a source branch otherwise. We
now have distgit branches ending with -rdo, e.g. newton-rdo, so
the code needs to be adjusted.

Change-Id: I22844700690454dab49cc017a1209b346b848b75

openstack-packages/delorean,openstack-packages/delorean,openstack-packages/DLRN,openstack-packages/DLRN