Update changelog for 6.2.2 (#17452)

* Update changelog

* Fix whitespace

CHANGELOG.md

 # 6.3.0 (unreleased)
 
+# 6.2.2 (2019-06-05)
+
+### Features / Enhancements
+  * **Security**: Prevent CSV formula injection attack when exporting data. [#17363](https://github.com/grafana/grafana/pull/17363), [@DanCech](https://github.com/DanCech)
+
+### Bug Fixes
+  * **CloudWatch**: Fixes error when hiding/disabling queries . [#17283](https://github.com/grafana/grafana/pull/17283), [@jpiccari](https://github.com/jpiccari)
+  * **Database**: Fixed slow permission query in folder/dashboard search. [#17427](https://github.com/grafana/grafana/pull/17427), [@aocenas](https://github.com/aocenas)
+  * **Explore**: Fixed updating time range before running queries. [#17349](https://github.com/grafana/grafana/pull/17349), [@marefr](https://github.com/marefr)
+  * **Plugins**: Fixed plugin config page navigation when using subpath. [#17364](https://github.com/grafana/grafana/pull/17364), [@torkelo](https://github.com/torkelo)
+
 # 6.2.1 (2019-05-27)
 
 ### Features / Enhancements