changelog: adds note for #11530

CHANGELOG.md

@@ -30,6 +30,7 @@
 * **Prometheus**: Escape backslash in labels correctly. [#10555](https://github.com/grafana/grafana/issues/10555), thx [@roidelapluie](https://github.com/roidelapluie)
 * **Variables**: Case-insensitive sorting for template values [#11128](https://github.com/grafana/grafana/issues/11128) thx [@cross](https://github.com/cross)
 * **Annotations (native)**: Change default limit from 10 to 100 when querying api [#11569](https://github.com/grafana/grafana/issues/11569), thx [@flopp999](https://github.com/flopp999)
+* **MySQL/Postgres/MSSQL**: PostgreSQL datasource generates invalid query with dates before 1970 [#11530](https://github.com/grafana/grafana/issues/11530) thx [@ryantxu](https://github.com/ryantxu)
 
 # 5.0.4 (2018-03-28)