Update CHANGELOG

Author: bouwew

CHANGELOG.md

@@ -4,7 +4,7 @@ Versions from 0.40 and up
 
 ## v0.57.5
 
-- Bump plugwise to [v1.7.7](https://github.com/plugwise/python-plugwise/releases/tag/v1.7.7) and adapt
+- Bump plugwise to [v1.7.7](https://github.com/plugwise/python-plugwise/releases/tag/v1.7.7) and adapt, small improvements
 
 ## v0.57.4