Fixed stupid NRE error.
Fixed stupid NRE error.

* src/Libraries/Hyena.Gui/Hyena.Widgets/ActionButton.cs: Fixed stupid
NRE error.

svn path=/trunk/banshee/; revision=3720

GNOME/hyena,arfbtwn/hyena,petejohanson/hyena,dufoli/hyena,dufoli/hyena,GNOME/hyena,petejohanson/hyena,arfbtwn/hyena