Make g_set_object more symmetric
Make g_set_object more symmetric

As argued in bug 748633, and order of ref, assign, unref is
preferable.

cention-sany/glib,tchakabam/glib,cention-sany/glib,ieei/glib,cention-sany/glib,johne53/MB3Glib,ieei/glib,tchakabam/glib,mzabaluev/glib,MathieuDuponchelle/glib,Distrotech/glib,johne53/MB3Glib,tchakabam/glib,endlessm/glib,johne53/MB3Glib,MathieuDuponchelle/glib,endlessm/glib,cention-sany/glib,Distrotech/glib,ieei/glib,ieei/glib,endlessm/glib,endlessm/glib,johne53/MB3Glib,johne53/MB3Glib,MathieuDuponchelle/glib,mzabaluev/glib,MathieuDuponchelle/glib,mzabaluev/glib,mzabaluev/glib,endlessm/glib,tchakabam/glib,cention-sany/glib,MathieuDuponchelle/glib,johne53/MB3Glib,Distrotech/glib,mzabaluev/glib,Distrotech/glib,ieei/glib,Distrotech/glib,tchakabam/glib