add fix to changelog

Author: Jiloc

CHANGELOG.md

@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to the versioning scheme outlined in the [README.md](README.md).
 
+## Unreleased
+
+### Fixed
+
+- Fixed a typo in the metrics_identifier route from `/v2/stackedb/:principal/:contract_name/replicas` to `/v2/stackerdb/:principal/:contract_name/replicas`. Note: This may be a breaking change for systems relying on the incorrect route. Please update any metrics tools accordingly.
+
 ## [3.2.0.0.0]
 
 ### Added