Update CHANGELOG.

CHANGELOG

@@ -9,6 +9,7 @@ v 8.6.0 (unreleased)
   - Return empty array instead of 404 when commit has no statuses in commit status API
   - Update documentation to reflect Guest role not being enforced on internal projects
   - Allow search for logged out users
+  - Don't show Issues/MRs from archived projects in Groups view
 
 v 8.5.2
   - Fix sidebar overlapping content when screen width was below 1200px