fix missing changelog link

Author: starkat99

CHANGELOG.md

@@ -77,7 +77,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 [@nicbn]: https://github.com/nicbn
 
-[Unreleased]: https://github.com/starkat99/widestring-rs/compare/v0.4.1...HEAD
+[Unreleased]: https://github.com/starkat99/widestring-rs/compare/v0.4.2...HEAD
+[0.4.2]: https://github.com/starkat99/widestring-rs/compare/v0.4.1...v0.4.2
 [0.4.1]: https://github.com/starkat99/widestring-rs/compare/v0.4.0...v0.4.1
 [0.4.0]: https://github.com/starkat99/widestring-rs/compare/v0.3.0...v0.4.0
 [0.3.0]: https://github.com/starkat99/widestring-rs/compare/v0.2.2...v0.3.0