docs(changelog): add update about fixed height legend

CHANGELOG.md

@@ -16,6 +16,7 @@
 * **mysql**: Grafana now supports ssl for mysql, closes [#3584](https://github.com/grafana/grafana/issues/3584)
 * **snapshot**: Annotations are now included in snapshots, closes [#3635](https://github.com/grafana/grafana/issues/3635)
 * **Admin**: Admin can now have global overview of Grafana setup, closes [#3812](https://github.com/grafana/grafana/issues/3812)
+* **graph**: Right side legend height is now fixed at row height, closes [#1277](https://github.com/grafana/grafana/issues/1277)
 
 ### Bug fixes
 * **Playlist**: Fix for memory leak when running a playlist, closes [#3794](https://github.com/grafana/grafana/pull/3794)