gtk3: remove a method call that raise an error on gtk3 gtk3/sample/misc/colorselection.rb
gtk3: remove a method call that raise an error on gtk3
gtk3/sample/misc/colorselection.rb

kitachro/ruby-gnome2,kitachro/ruby-gnome2,kitachro/ruby-gnome2,kitachro/ruby-gnome2,kitachro/ruby-gnome2