Update CHANGELOG

CHANGELOG

@@ -10,6 +10,7 @@ v 8.13.0 (unreleased)
   - Fix permission for setting an issue's due date
   - Expose expires_at field when sharing project on API
   - Fix robots.txt disallowing access to groups starting with "s" (Matt Harrison)
+  - Close open merge request without source project (Katarzyna Kobierska Ula Budziszewska)
   - Use a ConnectionPool for Rails.cache on Sidekiq servers
   - Only update issuable labels if they have been changed
   - Revoke button in Applications Settings underlines on hover.
@@ -21,7 +22,6 @@ v 8.13.0 (unreleased)
   - API: expose pipeline data in builds API (!6502, Guilherme Salazar)
   - Fix broken repository 500 errors in project list
   - Close todos when accepting merge requests via the API !6486 (tonygambone)
-  - Close open merge request without source project (Katarzyna Kobierska Ula Budziszewska)
 
 v 8.12.4 (unreleased)