Update CHANGELOG.md

Author: VincentD06

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 All notable changes to this project will be documented in this file.
 
+## [6.3.0](https://github.com/airbus-cyber/graylog-plugin-logging-alert/compare/6.1.7...6.3.0)
+### Changes
+* Change Graylog minimum version to 6.3.7
+
 ## [6.1.7](https://github.com/airbus-cyber/graylog-plugin-logging-alert/compare/6.1.6...6.1.7)
 ### Changes
 * Fully Remove Aggregation Feature ([issue #53](https://github.com/airbus-cyber/graylog-plugin-logging-alert/issues/53))