Add PR number to changelog

Author: Sephster

CHANGELOG.md

@@ -8,7 +8,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ### Fixed
 - If you provide a valid redirect_uri with the auth code grant and an invalid scope, the server will use the given 
-redirect_uri instead of the default client redirect uri
+redirect_uri instead of the default client redirect uri (PR #1126)
 
 
 ## [8.1.0] - released 2020-04-29