Update changelog

CHANGELOG.md

@@ -32,6 +32,7 @@ Please view this file on the master branch, on stable branches it's out of date.
 - New issue board list dropdown stays open after adding a new list
 - Fix: Backup restore doesn't clear cache
 - Optimize Event queries by removing default order
+- Remove duplicate links from sidebar
 - API: Fix project deploy keys 400 and 500 errors when adding an existing key. !6784 (Joshua Welsh)
 - Add job for removal of unreferenced LFS objects from both the database and the filesystem (Frank Groeneveld)
 - Replace jquery.cookie plugin with js.cookie !7085