Update CHANGELOG-EE.md for 13.5.1-ee

[ci skip]

CHANGELOG-EE.md

 Please view this file on the master branch, on stable branches it's out of date.
+## 13.5.1 (2020-10-22)
+
+- No changes.
+
 ## 13.5.0 (2020-10-22)
 ### Removed (1 change, 1 of them is from the community)