Improve change log for #2242

Author: JonRowe

Changelog.md

@@ -1,9 +1,9 @@
 ### Development
 [Full Changelog](https://github.com/rspec/rspec-rails/compare/v4.0.0.beta4...master)
 
-Enhancements:
+Bug Fixes:
 
-* Add the ability to change ActiveJob::Base.queue_adapter in system spec.
+* Allow changing `ActiveJob::Base.queue_adapter` inside a system spec.
   (Jonathan Rochkind, #2242)
 
 ### 4.0.0.beta4