Fix for minimal image build from submodule

If the minimal image is built from haf checked out as a submodule, it'll fail to start with error /home/haf_admin/docker_entrypoint.sh: line 22: /home/haf_admin/source/haf/scripts/copy_datadir.sh: No such file or directory

This is a fix for that issue.

assigned to @kbotor

enabled an automatic merge when all merge checks for 82e5ed3e pass

canceled the automatic merge

enabled an automatic merge when all merge checks for 82e5ed3e pass

merged