update changelog

Author: stevehu

CHANGELOG.md

@@ -5,8 +5,11 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/)
 and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [Unreleased]
+
 ### Added
 
+### Changed
+
 ## 1.0.53 - 2021-05-19
 
 ### Added
@@ -15,8 +18,6 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 - fixes #400 Introduce forceHttps flag in JsonSchemaFactory.Builder. Thanks @hisener
 
-### Changed
-
 ## 1.0.52 - 2021-04-13
 
 ### Added