Update CHANGELOG-EE.md for 11.6.5-ee

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CHANGELOG-EE.md

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+## 11.6.5 (2019-01-17)
+
+### Fixed (1 change)
+
+- Fix Error 500 when deleting a pipeline via the API. !9104
+
+
 ## 11.6.4 (2019-01-15)
 
 - No changes.

ee/changelogs/unreleased/sh-fix-delete-pipeline-api.yml

----
-title: Fix Error 500 when deleting a pipeline via the API
-merge_request: 9104
-author:
-type: fixed