update

Change log entry header was malformed.

Author: NoelStephensUnity

com.unity.netcode.gameobjects/CHANGELOG.md

@@ -6,7 +6,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 
 Additional documentation and release notes are available at [Multiplayer Documentation](https://docs-multiplayer.unity3d.com).
 
-## [2.8.1] - 2025-1-23
+## [2.8.1] - 2025-01-23
 
 ### Fixed