Fix CHANGELOG.

CHANGELOG-EE

 Please view this file on the master branch, on stable branches it's out of date.
-v 8.12.1 (unreleased)
+v 8.13.0 (unreleased)
+
+v 8.12.2 (unreleased)
+
+v 8.12.1
+- Prevent secrets to be pushed to the repository
 v 8.12.0
   - Include more data in EE usage ping