examples: threading/gtk_threading.py: fix __gtype_name__
examples: threading/gtk_threading.py: fix __gtype_name__

amremam2004/pygtk,amremam2004/pygtk,GNOME/pygtk,GNOME/pygtk,GNOME/pygtk,nzjrs/pygtk,Distrotech/pygtk,nzjrs/pygtk,amremam2004/pygtk,nzjrs/pygtk,Distrotech/pygtk,Distrotech/pygtk