Update CHANGELOG-EE.md for 13.7.9-ee

[ci skip]

CHANGELOG-EE.md

@@ -320,6 +320,10 @@ Please view this file on the master branch, on stable branches it's out of date.
 - Enable DevOps Adoption Report feature flag if any Segments already exist. !51602
+## 13.7.9 (2021-03-17)
+
+- No changes.
+
 ## 13.7.8 (2021-03-04)
 - No changes.