glib-2.0: don't use the container type's generic in static methods
glib-2.0: don't use the container type's generic in static methods

Fixes bug 669816.

GNOME/vala,GNOME/vala,GNOME/vala,frida/vala,spidermonkdust/vala,rvu95/vala,rvu95/vala,frida/vala,frida/vala,GNOME/vala,spidermonkdust/vala,rvu95/vala,flobrosch/vala-fixes,spidermonkdust/vala,frida/vala,flobrosch/vala-fixes,frida/vala,flobrosch/vala-fixes