Add changelog entry for the debug information addition for 'this is not a release branch'

Author: oguzkocer

CHANGELOG.md

@@ -20,6 +20,7 @@ _None_
 
 - Add "Mobile Secrets" to `configure_update` current branch message to clarify which repo it's referring to. [#455]
 - `buildkite_trigger_build` now prints the web URL of the newly scheduled build, to allow you to easily open it via cmd-click. [#460]
+- Add the branch information to the 'This is not a release branch' error that's thrown from complete code freeze lane. [#461]
 
 ## 7.0.0