changelog: add notes about closing #12240

[skip ci]

CHANGELOG.md

@@ -29,6 +29,7 @@
 ### 5.2.0-beta1 fixes
 
 * **Dashboard**: Dashboard link doesn't work when "As dropdown" option is checked [#12315](https://github.com/grafana/grafana/issues/12315)
+* **Dashboard**: Fix regressions after save modal changes, including adhoc template issues [#12240](https://github.com/grafana/grafana/issues/12240)
 
 # 5.2.0-beta1 (2018-06-05)