Add Changelog entry for pipeline settings button fix

CHANGELOG.md

@@ -2,6 +2,7 @@ Please view this file on the master branch, on stable branches it's out of date.
 
 ## 8.13.0 (2016-10-22)
 
+  - Fix save button on project pipeline settings page. (!6955)
   - Avoid race condition when asynchronously removing expired artifacts. (!6881)
   - Improve Merge When Build Succeeds triggers and execute on pipeline success. (!6675)
   - Respond with 404 Not Found for non-existent tags (Linus Thiel)