Add Changelog entry for build status canceled fix

CHANGELOG

 Please view this file on the master branch, on stable branches it's out of date.
 
 v 8.8.0 (unreleased)
+  - Make build status canceled if any of the jobs was canceled and none failed
   - Remove future dates from contribution calendar graph.
   - Fix error when visiting commit builds page before build was updated
   - Add 'l' shortcut to open Label dropdown on issuables and 'i' to create new issue on a project