Steps to reproduce:

1. in `Administration` -> create users, user roles and groups, then assign to ourselves services, host groups etc.
2. in `Monitoring-> Maps` create a map and setup sharing
3. As user A of group A-group view `Monitoring ->Maps` and see every maps which contains image element.
4. As user B of group B-group view --//---

Result:
User of B-group can see maps of A-group and vice versa.
When i remove image and use only other element type,  then visibility is ok. But it is ignored sharing permissions
Expected:
When I set sharing the affects groups/users can read the maps.

When I set image element into map, nobody can not see my maps except shared list groups/users.