Notification shown even if no Notification Provider is selected

Description

Steps to reproduce

1. Navigate to the Language Manager's Settings page.
2. In the Notification Provider section, choose the type User Notification, then click Save.
3. Import a translation package to trigger the notification message.
4. Go to the Settings page again.
5. For User Notification type, choose blank then click Save.
6. Import a translation package again

Expected: Notification message should not appear.

Actual: Notification message appears.