release year fix

Author: fernando-cortez

Packages/com.unity.multiplayer.samples.coop/CHANGELOG.md

@@ -4,6 +4,6 @@ All notable changes to this project template will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
-## [0.1.0-experimental] - 2020-04-07
+## [0.1.0-experimental] - 2021-04-07
 
 ### This is the experimental release of *Small scale coop sample - Boss Room*.