docs(): updated changelog

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## Enhancements
 * **Alerting**: Added Telegram alert notifier [#7098](https://github.com/grafana/grafana/pull/7098), thx [@leonoff](https://github.com/leonoff)
+* **Templating**: Make $__interval and $__interval_ms global built in variables that can be used in by any datasource (in panel queries), closes [#7190](https://github.com/grafana/grafana/issues/7190), closes [#6582](https://github.com/grafana/grafana/issues/6582)
 
 # 4.1.0 (2017-01-11)