Allow running gdbus-peer inside a container
Allow running gdbus-peer inside a container

The /etc/machine-id inside a Docker container is allowed to be empty, so
we need to check for that case.

https://bugzilla.gnome.org/show_bug.cgi?id=793635

endlessm/glib,endlessm/glib,endlessm/glib,endlessm/glib,endlessm/glib