Update CHANGELOG-EE.md for 8.16.6-ee

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CHANGELOG-EE.md

 Please view this file on the master branch, on stable branches it's out of date.
 
+## 8.16.6 (2017-02-17)
+
+- Geo: send the new event type with the backfill function. !1157
+- Move RepositoryUpdateRemoteMirrorWorker jobs to project_mirror Sidekiq queue. !1234
+- Fixed merge request environment link not displaying.
+- Reduce queries needed to check if node is a primary or secondary Geo node.
+
 ## 8.16.5 (2017-02-14)
 
 - No changes.

changelogs/unreleased-ee/1645-backfill.yml

----
-title: 'Geo: send the new event type with the backfill function'
-merge_request: 1157
-author:

changelogs/unreleased-ee/merge-request-enrvironments-link.yml

----
-title: Fixed merge request environment link not displaying
-merge_request:
-author:

changelogs/unreleased-ee/mrchrisw-move-remoteupdateworker.yml

----
-title: Move RepositoryUpdateRemoteMirrorWorker jobs to project_mirror Sidekiq queue
-merge_request: 1234
-author:

changelogs/unreleased-ee/sh-fix-geo-node-cache.yml

----
-title: Reduce queries needed to check if node is a primary or secondary Geo node
-merge_request:
-author: