scrolledwindow: Make kinetic scrolling only work on touch devices
scrolledwindow: Make kinetic scrolling only work on touch devices

This code was relying on the previous GtkGestureSingle::touch-only default
value, so restore the behavior back.

https://bugzilla.gnome.org/show_bug.cgi?id=734285

alexlarsson/gtk,ahodesuka/gtk,Adamovskiy/gtk,jadahl/gtk,jigpu/gtk,jigpu/gtk,Lyude/gtk-,alexlarsson/gtk,alexlarsson/gtk,alexlarsson/gtk,jigpu/gtk,davidgumberg/gtk,chergert/gtk,chergert/gtk,Lyude/gtk-,chergert/gtk,grubersjoe/adwaita,Adamovskiy/gtk,alexlarsson/gtk,grubersjoe/adwaita,Adamovskiy/gtk,grubersjoe/adwaita,jadahl/gtk,Adamovskiy/gtk,alexlarsson/gtk,jessevdk/gtk,jadahl/gtk,Lyude/gtk-,grubersjoe/adwaita,jadahl/gtk,Lyude/gtk-,jigpu/gtk,davidgumberg/gtk,ahodesuka/gtk,davidgumberg/gtk,alexlarsson/gtk,ahodesuka/gtk,davidgumberg/gtk,Lyude/gtk-,Lyude/gtk-,chergert/gtk,jigpu/gtk,alexlarsson/gtk,jadahl/gtk,ahodesuka/gtk,ahodesuka/gtk,jigpu/gtk,jadahl/gtk,grubersjoe/adwaita,Lyude/gtk-,jessevdk/gtk,chergert/gtk,Adamovskiy/gtk,davidgumberg/gtk,ahodesuka/gtk,davidgumberg/gtk,chergert/gtk,Adamovskiy/gtk,chergert/gtk,davidgumberg/gtk,jessevdk/gtk,grubersjoe/adwaita,jessevdk/gtk,grubersjoe/adwaita,Adamovskiy/gtk,jessevdk/gtk,chergert/gtk,jessevdk/gtk,ahodesuka/gtk,jigpu/gtk,ahodesuka/gtk,Adamovskiy/gtk,jadahl/gtk,jigpu/gtk,davidgumberg/gtk,Lyude/gtk-,jessevdk/gtk,jadahl/gtk,grubersjoe/adwaita