Update CHANGELOG for "Auto git fsck"

CHANGELOG

@@ -27,6 +27,7 @@ v 8.7.0 (unreleased)
   - Add endpoints to archive or unarchive a project !3372
   - Add links to CI setup documentation from project settings and builds pages
   - Handle nil descriptions in Slack issue messages (Stan Hu)
+  - Add automated repository integrity checks
   - API: Expose open_issues_count, closed_issues_count, open_merge_requests_count for labels (Robert Schilling)
   - API: Ability to star and unstar a project (Robert Schilling)
   - Add default scope to projects to exclude projects pending deletion