Remove RELEASE-NOTES entry added in
r43377 (Factored wfInvokeFancyCallback() out of wfRunHooks()) and tweaked in
r43379 (Renamed the new wfInvokeFancyCallback to simply wfInvoke). RELEASE-NOTES is intended for user-visible changes. Internal refactorings like the wfInvoke() thing shouldn't be listed there.