Add permissions tot the UserAdapter/API as well.

The button on the user browse page is available based on the
UserAdapter, not the entity.

Author: alexdryden

Module.php

@@ -254,6 +254,11 @@ protected function addAclRules()
                 ['create', 'delete', 'change-password', 'edit-keys']
             );
 
+            $acl->deny(
+                'site_admin',
+                'Omeka\Api\Adapter\UserAdapter',
+                ['create', 'delete']
+            );
         }
 
         $acl->allow(