gtk3: use false for the default value of Gtk::Paned#pack1(:resize)
gtk3: use false for the default value of Gtk::Paned#pack1(:resize)

Because `gtk_paned_add1()` is equivalent to `gtk_paned_pack1(widget,
FALSE, TRUE)`.

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