[gi-invoke-ng] return None when appropriate so we don't crash
[gi-invoke-ng] return None when appropriate so we don't crash

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