update changelog with bug fix notes

Author: littleaj

CHANGELOG.md

@@ -36,6 +36,9 @@
 - Removed support for `<Class>` custom instrumentation in `AI-Agent.xml`
 - Removed support for `<RuntimeException>` custom instrumentation in `AI-Agent.xml`
 
+# Version 2.4.1
+- Fix [#910](https://github.com/microsoft/ApplicationInsights-Java/issues/910) Fixed correlation id serialization.
+
 # Version 2.4.0
 - Updated Spring Boot Starter version number to track with the SDK version.
 - Upgrade gradle to 5.3.1