Fix gail_notebook_get_selection_count()
Fix gail_notebook_get_selection_count()

This function should return 0 for empty notebooks. Based on
a patch by Mike Gorse, bug 557263.
(cherry picked from commit 7844d3b8db94922ff17a598d6b36dd30ea0d569d)

Distrotech/gtk,Unity-Technologies/gtk,johne53/MB3Gtk-2,Distrotech/gtk,Distrotech/gtk,johne53/MB3Gtk-2,Unity-Technologies/gtk,johne53/MB3Gtk-2,johne53/MB3Gtk-2,johne53/MB3Gtk-2,Distrotech/gtk,Unity-Technologies/gtk,Unity-Technologies/gtk,Unity-Technologies/gtk,Distrotech/gtk