Page Only Notification filters get deleted when a page is renamed/moved

Steps to reproduce

1. Login as Admin
2. Create an user (e.g. U1)
3. Login as U1 (which by default has Watch Toggles to OFF)
4. Create a page (e.g. P1) in order to be watched automatically (and to be added as filter preference)
5. Login as Admin
6. Rename/move the page 'P1' to 'P2'
7. Login with the user U1
8. Go to Notifications Settings and observe the filter for page previously created (and then renamed)

Expected results

The filter preference for the page 'P1' has been updated to 'P2'.

Actual results

The filter is deleted.

The issue could not be reproduced on XWiki 15.10.1 and XWiki 14.10.20.