Merge branch 'kerberos-changelog' into 'master'

Mention Kerberos in CHANGELOG-EE

This was forgotten in https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/548

See merge request !574

CHANGELOG-EE

@@ -8,6 +8,7 @@ v 8.10.0 (unreleased)
   - Isolate EE LDAP library code in EE module (Part 1) !511
   - Make Elasticsearch indexer run as an async task
   - Fix of removing wiki data from index when project is deleted
+  - Ticket-based Kerberos authentication (SPNEGO)
 
 v.8.9.7 (unreleased)
   - Fix error in admin dashboard when Geo is enabled and current node is nil.