Adjust repo namespace for pbr

This is a follow up for change Ifcfce490edb3d77e4e436e002d35bc909e1a057c
where the GIT_BASE was changed to the opendev URL to avoid redirects.
The pbr namespace in stackrc was old and still getting redirected and
this change fixes that.

Change-Id: Ib444e928fa2ca7650670f97be6927202333a1dd7
1 file changed