Update CHANGELOG.md

Author: GrahamTheCoder

CHANGELOG.md

@@ -16,7 +16,6 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 * Don't generate unnecessary properties for WithEvents fields [#572](https://github.com/icsharpcode/CodeConverter/issues/572)
 
 ### C# -> VB
-* Performance increase for large files/projects
 
 ## [8.1.6] - 2020-07-12