changelog: adds note about closing #7482

CHANGELOG.md

@@ -15,6 +15,7 @@
 * **Alerting**: Adds de duping of alert notifications [#7632](https://github.com/grafana/grafana/pull/7632)
 * **Orgs**: Sharing dashboards using Grafana share feature will not redirect to correct org. [#1613](https://github.com/grafana/grafana/issues/1613)
 * **Pushover**: Add Pushover alert notifications [#7526](https://github.com/grafana/grafana/pull/7526) thx [@devkid](https://github.com/devkid)
+* **Threema**: Add Threema Gateway alert notification integration [#7482](https://github.com/grafana/grafana/pull/7482) thx [@dbrgn](https://github.com/dbrgn)
 
 ## Minor Enhancements
 * **Optimzation**: Never issue refresh event when Grafana tab is not visible [#7218](https://github.com/grafana/grafana/issues/7218), thx [@mtanda](https://github.com/mtanda)