Remove gerrit message for unknown failures

The gerrit messages on negative failures are redundant because the
wiki link is already in the zuul failure message.

README.md

@@ -13,7 +13,6 @@ Future Work
 ------------
 - Pull in list of queries from a more flexible source, so a commit isn't needed to update each time
 - Make unit tests robust and not need internet
-- Add Gerrit Comments to failed jobs
 - Write tests to validate queries.json
 - Use cookiecutter to clean this repo up
 

bot.py

@@ -130,7 +130,6 @@ class RecheckWatch(threading.Thread):
             bug_number = classifier.classify(change, rev, event['comment'])
             if bug_number is None:
                 self._read(event)
-                stream.leave_comment(project, change_id)
             else:
                 event['bug_number'] = bug_number
                 self._read(event)