changelog: add notes about closing #12533

[skip ci]

CHANGELOG.md

@@ -30,6 +30,7 @@
 * **Dashboard**: Dashboard links not updated when changing variables [#12506](https://github.com/grafana/grafana/issues/12506)
 * **Postgres/MySQL/MSSQL**: Fix connection leak [#12636](https://github.com/grafana/grafana/issues/12636) [#9827](https://github.com/grafana/grafana/issues/9827)
 * **Dashboard**: Remove unwanted scrollbars in embedded panels [#12589](https://github.com/grafana/grafana/issues/12589)
+* **Prometheus**: Prevent error using $__interval_ms in query [#12533](https://github.com/grafana/grafana/pull/12533)
 
 # 5.2.1 (2018-06-29)