wayland: Update grab serial when ungrabbing keyboards
wayland: Update grab serial when ungrabbing keyboards

This was being done so only on pointers. Internally, a GdkDeviceGrabInfo
is kept for each of the master pointer/keyboard, failing to do this for
keyboards results in a stuck keyboard grab.

https://bugzilla.gnome.org/show_bug.cgi?id=748892

Adamovskiy/gtk,jadahl/gtk,alexlarsson/gtk,chergert/gtk,grubersjoe/adwaita,jadahl/gtk,Adamovskiy/gtk,jigpu/gtk,davidgumberg/gtk,Adamovskiy/gtk,davidgumberg/gtk,chergert/gtk,grubersjoe/adwaita,alexlarsson/gtk,chergert/gtk,Adamovskiy/gtk,grubersjoe/adwaita,alexlarsson/gtk,grubersjoe/adwaita,alexlarsson/gtk,alexlarsson/gtk,alexlarsson/gtk,jadahl/gtk,Adamovskiy/gtk,grubersjoe/adwaita,Adamovskiy/gtk,jigpu/gtk,jadahl/gtk,chergert/gtk,davidgumberg/gtk,chergert/gtk,chergert/gtk,chergert/gtk,grubersjoe/adwaita,davidgumberg/gtk,jadahl/gtk,jadahl/gtk,jigpu/gtk,jadahl/gtk,jigpu/gtk,alexlarsson/gtk,chergert/gtk,jigpu/gtk,alexlarsson/gtk,jigpu/gtk,Adamovskiy/gtk,grubersjoe/adwaita,jigpu/gtk,davidgumberg/gtk,Adamovskiy/gtk,grubersjoe/adwaita,jadahl/gtk,davidgumberg/gtk,davidgumberg/gtk,jigpu/gtk,davidgumberg/gtk