The ajax delete comment tests are intermittently failing. Many of the assertions make it hard to tell why they are failing. This adds a message to one of those assertions that contains some info on what is being asserted with the goal that it helps developers understand why the failure is failing.
See #33968
git-svn-id: https://develop.svn.wordpress.org/trunk@34879 602fd350-edb4-49c9-b593-d223f7449a82
