Remove beta.4 reference from version links

Author: justin808

CHANGELOG.md

@@ -1844,8 +1844,7 @@ such as:
 - Fix several generator-related issues.
 
 [unreleased]: https://github.com/shakacode/react_on_rails/compare/v16.2.0.beta.10...master
-[v16.2.0.beta.10]: https://github.com/shakacode/react_on_rails/compare/16.2.0.beta.4...v16.2.0.beta.10
-[16.2.0.beta.4]: https://github.com/shakacode/react_on_rails/compare/16.1.1...16.2.0.beta.4
+[v16.2.0.beta.10]: https://github.com/shakacode/react_on_rails/compare/16.1.1...v16.2.0.beta.10
 [16.1.1]: https://github.com/shakacode/react_on_rails/compare/16.1.0...16.1.1
 [16.1.0]: https://github.com/shakacode/react_on_rails/compare/16.0.0...16.1.0
 [16.0.0]: https://github.com/shakacode/react_on_rails/compare/14.2.0...16.0.0