This change employs the same approach as [1] for Release.key.
Change-Id: Ic51d6e6557ee0b56d21d8ff4feaf04bc02e41a2e
Related: [1] I3ec86c8610b3b43d39ea8e3da444861d317ced4e
This allows easily changing to another osmocom repo base URL if the
default one is down.
Related: OS#4862
Change-Id: I8010b08f3dabacfb3c13a44eece6c7a490e0742e
This is initialized to docker.io, keeping the default behaviour
if not specified. However, it allows us to specify a private
registry later on.
Related: OS#4839
Change-Id: I32d4ee6256033c809108c1b86cb6b6c58d880f49
Let's use the "ADD" trick that we use for git repositories also for
the osmocom:nightly debian package feed. This way any change to the
package feed will result in a rebuild of the container.