x11: don't create the libinput tapping property
x11: don't create the libinput tapping property

If it doesn't exist, we don't have a touchpad. Don't create the property
and potentially confuse other pieces of the stack that do the same check.

GNOME/clutter,GNOME/clutter,jigpu/clutter,GNOME/clutter,jigpu/clutter,Distrotech/clutter,GNOME/clutter,Distrotech/clutter,GNOME/clutter,jigpu/clutter,Distrotech/clutter,Distrotech/clutter,jigpu/clutter,Distrotech/clutter,Distrotech/clutter,jigpu/clutter,jigpu/clutter