Add logger warning for queued jobsteps that aren't found in the Jenki…

…ns queue

Summary:
The above TODO is one we should probably follow up on, but for now it'd be nice
to be able to track how often this happens and to be able to easily check
whether this was the reason when a build fails.

Test Plan: None

Reviewers: jukka

Reviewed By: jukka

Subscribers: changesbot, wwu

Differential Revision: https://tails.corp.dropbox.com/D97455

changes/backends/jenkins/builder.py

@@ -517,6 +517,7 @@ def _sync_step_from_queue(self, step):
             step.status = Status.finished
             step.result = Result.unknown
             db.session.add(step)
+            self.logger.warning("Queued step not found in queue: {} (build: {})".format(step.id, step.job.build_id))
             return
 
         if item.get('executable'):