don't return userlist for ldap (=all users)

page_authz_policy_editor/pape_admin.py

@@ -110,8 +110,7 @@ class PageAuthzPolicyEditor(Component):
             return None
 
     def _get_users(self):
-        user_list = ', '.join(self.account_manager.get_users())
-        return user_list
+        return None
 
     # Get the groups and their members so they can easily be included
     # in the groups section of the authz file. Need it as a dictionary