modify

UpdateManager/UpdateManagerDbus.py

@@ -118,7 +118,9 @@ class UpdateManagerDbusController(dbus.service.Object):
             if self.transaction.cancellable == True:
                 self.transaction.cancel()
                 status = True
-                message = "success"
+                message = "Success"
+            elif self.transaction == None or self.transaction.cancellable == False:
+                message = "Can not Cancel"
         except Exception as e:
             return (status,str(e))
         return (status, message)