Using 3.5 nightly repo for fc19 builds

Ovirt engine no longer builds for fc19, so for the extensions we need to use the
3.5 nightly repos instead of master.

Change-Id: I7b471d21d6280c94199b3bda38e341dcd08545ca
Signed-off-by: David Caro <dcaroest@redhat.com>