Remove redundant message notification read redirect URL parameter

Prerequisite: You need access to your test Moodle site's SQL database to fetch some notification IDs.

Setup

1. Have a Moodle site with at least 3 users (referred to as user A, user B and user C).

Testing

1. Login as user A.
2. Send a contact request from user A to user B. (see the video attached for how to do this contact-request.mp4)
3. In your Moodle site's SQL database, in the 'notifications' table (eg mdl_notifications), find the most recent entry (highest ID), which should have the subject "Contact request from user A". Note down the value from the "id" column (referred to later as value 1).
4. Send a contact request from user A to user C.
5. In your Moodle site's SQL database, refresh your view of the 'notifications' table, and again find the most recent entry (highest ID), which should have the subject "Contact request from user A", and have an ID at least one larger than the one noted in the previous step. Note down the value from the "id" column (referred to later as value 2).
6. Login as user B.
7. Navigate to the following link, replacing <wwwroot> with your site's host root (eg localhost/stable_master), and replacing <ID HERE> with the ID you noted down as value 1.

   <wwwroot>/message/output/popup/mark_notification_read.php?notificationid=<ID HERE>&redirecturl=http%3A%2F%2Fgoogle.com

8. **CONFIRM you are redirected to user B's contact requests page (<wwwroot>/message/index.php?view=contactrequests). (If the patch is not applied, that link should redirect you to Google).
9. Navigate to the same link as step 7, but replace the notificationid number with the ID you noted down as value 2.
10. **CONFIRM you are redirected to the site homepage.