Update CHANGELOG.md

Author: marickvantuil

CHANGELOG.md

@@ -4,6 +4,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
+## 3.6.1 - 2023-09-01
+
+**Changed**
+
+- Updated PHPSeclib from 2.x to 3.x
+
 ## 3.6.0 - 2023-07-02
 
 **Changed**