Add checks if adjustments exist when stopping animation
Add checks if adjustments exist when stopping animation

Necessary when dispose() is called before the stop method when destroying
the objects.

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