How to disable Domain Mapping menu for admins?

Hi,

I'm using Domain Mapping plugin and I want to disable the Domain Mapping menu for everybody. Only me, the Super Admin want to see this menu.

I guess this is possible, because I have found a filter for this:

return apply_filters("dm_is_site_permitted", $this->_permitted);

Please help me how can I use this filter to hide this menu for everybody, but Super Administrators.

Thank you!