chore: remove duplicate "map updated" message

It is already handled by the front-end, and as it also handle the
"map created" message (including anonymous link form), I arbitrated
to keep all front-end side

umap/views.py

@@ -776,7 +776,6 @@ class MapUpdate(FormLessEditMixin, PermissionsMixin, UpdateView):
             id=self.object.pk,
             url=self.object.get_absolute_url(),
             permissions=self.get_permissions(),
-            info=_("Map has been updated!"),
         )