When messaging is turned off on a site, notification counter is hidden in navbar.

On Moodle sites where messaging is disabled, the notification counter in the navbar does not indicate how many new notifications a user has and remains hidden.

This has been tested and replicated using both Clean and Boost themes

To replicate:

1. Make sure that web notifications are turned on with the test user
2. Enable messaging on the site
3. Complete an action that triggers a notification like submitting an assignment
4. Confirm that the notification counter works as intended.
5. Now turn off messaging on the site. *** Note the previous notification will stay until cleared. Clear the notification.
6. Submit another assignment or any other task that triggers a notification.
7. Confirm that the notification counter will not be displayed, click on the icon and confirm that the notification is there in the list, just not shown in the counter.

Possibly related to MDL-45411 that was closed because it was supposedly fixed by MDL-54682  and the new messaging interface in 3.2