Map widget does not update map image on Apply button press

Steps to reproduce:

1. Open dashboard with Map widget on it.
2. Open Edit widget popup on the map widget and change map to another one.
3. Click Apply.
4. Observe: Map image have not changed.
5. Click Save changes to save the dashboard.
6. Observe: Map image have changed.

Result:
Map image get updated only after saving of a dashboard.
Expected:
Map image get updated after Apply button press in edit widget popup.