Add helptext for "Admin-ish" field when editing Role

tailbone/views/roles.py

@@ -180,7 +180,11 @@ class RoleView(PrincipalMasterView):
         f.set_validator('name', self.unique_name)
 
         # adminish
-        if not self.request.is_admin:
+        if self.request.is_admin:
+            f.set_helptext('adminish',
+                           "If checked, only Administrators may add/remove "
+                           "users for the role.")
+        else:
             f.remove('adminish')
 
         # session_timeout