docs: add note for #7614

CHANGELOG.md

@@ -10,6 +10,7 @@
 ## Minor Enchancements
 
 * **Prometheus**: Make Prometheus query field a textarea [#7663](https://github.com/grafana/grafana/issues/7663), thx [@hagen1778](https://github.com/hagen1778)
+* **Templating**: Should not be possible to create self-referencing (recursive) template variable definitions [#7614](https://github.com/grafana/grafana/issues/7614) thx [@thuck](https://github.com/thuck)
 
 # 4.2.0-beta2 (unreleased)
 ## Minor Enhancements