Update changelog

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 [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## Unreleased
+
+### Fixed
+
+- Fixed a memory leak related to the server's timezone (behind UTC) in the data gathering
+
 ## 2.3.0 - 2023-09-17
 
 ### Added
@@ -48,7 +54,6 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Fixed the timeout in _EOD Historical Data_ requests
 - Fixed an issue with the portfolio summary caused by the language localization for Dutch (`nl`)
-- Fixed a memory leak related to the server's timezone (behind UTC) in the data gathering
 
 ## 2.0.0 - 2023-09-09