Fixup changelog

Author: erikjohnston

CHANGES.md

@@ -25,10 +25,7 @@ Internal Changes
 Synapse 1.39.0rc2 (2021-07-22)
 ==============================
 
-Bugfixes
---------
-
-- Always include `device_one_time_keys_count` key in `/sync` response to work around a bug in Element Android that broke encryption for new devices. ([\#10457](https://github.com/matrix-org/synapse/issues/10457))
+This release also includes the changes in v1.38.1.
 
 
 Internal Changes