Update CHANGELOG.md

Author: offtherailz

CHANGELOG.md

@@ -3,8 +3,6 @@
 
 ## [2021.01.04](https://github.com/geosolutions-it/MapStore2/tree/v2021.01.04) (2021-06-28)
 
-This release contains hotfix for issue with CesiumJS certificate (#6838).
-
 - **[Full Changelog](https://github.com/geosolutions-it/MapStore2/compare/v2021.01.03...v2021.01.04)**
 
 - **[Implemented enhancements](https://github.com/geosolutions-it/MapStore2/issues?q=is%3Aissue+milestone%3A%222021.01.04%22+is%3Aclosed+label%3Aenhancement)**