changelog: add notes about closing #13815

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 * **Elasticsearch**: Add support for offset in date histogram aggregation [#12653](https://github.com/grafana/grafana/issues/12653), thx [@mattiarossi](https://github.com/mattiarossi)
 * **Auth**: Prevent password reset when login form is disabled or either LDAP or Auth Proxy is enabled [#14246](https://github.com/grafana/grafana/issues/14246), thx [@SilverFire](https://github.com/SilverFire)
+* **Dataproxy**: Override incoming Authorization header [#13815](https://github.com/grafana/grafana/issues/13815), thx [@kornholi](https://github.com/kornholi)
 
 # 5.4.0 (2018-12-03)