[gtk-demo] pixbuf.py: fix image loading
[gtk-demo] pixbuf.py: fix image loading

MathieuDuponchelle/pygobject,GNOME/pygobject,davidmalcolm/pygobject,davibe/pygobject,pexip/pygobject,MathieuDuponchelle/pygobject,davidmalcolm/pygobject,thiblahute/pygobject,GNOME/pygobject,thiblahute/pygobject,sfeltman/pygobject,jdahlin/pygobject,sfeltman/pygobject,choeger/pygobject-cmake,davidmalcolm/pygobject,sfeltman/pygobject,pexip/pygobject,jdahlin/pygobject,davibe/pygobject,MathieuDuponchelle/pygobject,davibe/pygobject,pexip/pygobject,choeger/pygobject-cmake,jdahlin/pygobject,thiblahute/pygobject,davibe/pygobject,choeger/pygobject-cmake,GNOME/pygobject