mx: update in_drag when not dragging
mx: update in_drag when not dragging

Probably bug in mx - there's nothing like setting in_drag to
false when dragging stops.

Distrotech/libchamplain,GNOME/libchamplain,StanciuMarius/Libchamplain-map-wrapping,Distrotech/libchamplain,PabloCastellano/libchamplain,StanciuMarius/Libchamplain-map-wrapping,Distrotech/libchamplain,PabloCastellano/libchamplain,Distrotech/libchamplain,GNOME/libchamplain,PabloCastellano/libchamplain,Distrotech/libchamplain,StanciuMarius/Libchamplain-map-wrapping,StanciuMarius/Libchamplain-map-wrapping,PabloCastellano/libchamplain,PabloCastellano/libchamplain,StanciuMarius/Libchamplain-map-wrapping