CHANGELOG entry

Author: utkarshcmu

CHANGELOG.md

@@ -11,6 +11,7 @@
 * **Scripts**: Use restart instead of start for deb package script, closes [#5282](https://github.com/grafana/grafana/pull/5282)
 * **Logging**: Moved to structured logging lib, and moved to component specific level filters via config file, closes [#4590](https://github.com/grafana/grafana/issues/4590)
 * **Search**: Add search limit query parameter, closes [#5292](https://github.com/grafana/grafana/pull/5292)
+* **OpenTSDB**: Support nested template variables in tag_values function, closes [4398](https://github.com/grafana/grafana/issues/4398)
 
 ## Breaking changes
 * **Logging** : Changed default logging output format (now structured into message, and key value pairs, with logger key acting as component). You can also no change in config to json log ouput.