We need the same RPMs to work equally well on a host running a beta
release (pulling beta content) as on a machine running GA (pulling GA
content). Detect this at run-time and point at the right repository.
Testing this is a bit hairy as we are building 8.3 images, but obviously
there is currently no 8.3 content at the GA URLs.
Signed-off-by: Tom Gundersen <teg@jklm.no>
