MAINTAINER is deprecated, drop the line in all Dockerfiles as suggested by Vadim. Related: https://docs.docker.com/engine/reference/builder/#maintainer-deprecated Change-Id: If1ef3032af2075d792c526ae744ec4c0c091da3a
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