Update CHANGELOG-EE.md for 9.2.7-ee

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CHANGELOG-EE.md

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+## 9.2.7 (2017-06-21)
+
+- Geo: fixed Dynamic Backoff strategy that was not being used by workers. !2128
+- fix Rebase being disabled for unapproved MRs.
+
 ## 9.2.6 (2017-06-16)
 
 - Geo: backported fix from 9.3 for big repository sync issues. !2000

changelogs/unreleased-ee/2385-rebase-without-approvals.yml

----
-title: fix Rebase being disabled for unapproved MRs
-merge_request:
-author:

changelogs/unreleased-ee/2639-geo-dynamic-backoff-strategy-is-not-working.yml

----
-title: 'Geo: fixed Dynamic Backoff strategy that was not being used by workers'
-merge_request: 2128
-author: