Python-gobject update to 3.0.4, for bluez-simple-agent to work

This makes 'bluez' python programs work (they import gi.repository, iirc), like bluez-simple-agent. But I don't know if it breaks things.

bluez-simple-agent is what I use to authenticate bluetooth devices, so for me it is important to have it working.

It'd be nice if some python maintainer could take a look; if it breaks things, we can have two pygobject.