update CHANGELOG.md to reflect !7085

CHANGELOG.md

@@ -10,6 +10,7 @@ Please view this file on the master branch, on stable branches it's out of date.
   - Add hover to trash icon in notes !7008 (blackst0ne)
   - Simpler arguments passed to named_route on toggle_award_url helper method
   - Fix: Backup restore doesn't clear cache
+  - Replace jquery.cookie plugin with js.cookie !7085
   - Use MergeRequestsClosingIssues cache data on Issue#closed_by_merge_requests method
   - Fix Sign in page 'Forgot your password?' link overlaps on medium-large screens
   - Fix documents and comments on Build API `scope`