update changelog

Author: mikesposito

packages/keyring-controller/CHANGELOG.md

@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 
+- Discard keyrings with duplicate accounts when unlock the wallet ([#5775](https://github.com/MetaMask/core/pull/5775))
 - Metadata for unsupported keyring is removed on unlock ([#5725](https://github.com/MetaMask/core/pull/5725))
 
 ## [21.0.6]