WIP'ed patch that is approved won't get picked up

[Andreas Jaeger]

Zuul was not picking up this revew: https://review.openstack.org/#/c/67223/

From IRC log:
09:56:33 PM - fungi: Ajaeger: was it wip when it got approved?
09:56:52 PM - Ajaeger: fungi: yes, it was. And then I approved it again
09:57:48 PM - fungi: Ajaeger: we may have a hole in our layout.yaml gate enqueuing logic there, if the change already has +2 vrfy and it not merged
09:58:45 PM - fungi: Ajaeger: i just rechecked it... it will re-gate after the current check run finishes. please open a bug about this against openstack-ci so we remember to address it

What happened:
* Patch was WIP
* Patch got approved by Diane
* Patch was verified but not merged
* WIP removed
* Approved by Andreas
* Still no action...

[Jeremy Stanley (fungi)]

Apparently this is a deeper problem than simple enqueuing logic issues...

[...]
2014-02-25 02:40:26,256 INFO zuul.DependentPipelineManager: Reporting change <Change 0x7f4a77ec0950 67223,4>, actions: [<ActionReporter <zuul.reporter.gerrit.Reporter object at 0x2d3a9d0>, {'verified': 2, 'submit': True}>]
2014-02-25 02:40:26,399 INFO zuul.Gerrit: Updating information for 67223,4
2014-02-25 02:40:26,634 INFO zuul.DependentPipelineManager: Reported change <Change 0x7f4a77ec0950 67223,4> status: all-succeeded: True, merged: False
2014-02-25 02:40:26,656 INFO zuul.Gerrit: Updating information for 67223,4
2014-02-25 02:40:26,726 ERROR zuul.Scheduler: Exception in run handler:
Traceback (most recent call last):
  File "/usr/local/lib/python2.7/dist-packages/zuul/scheduler.py", line 703, in run
    self.process_event_queue()
  File "/usr/local/lib/python2.7/dist-packages/zuul/scheduler.py", line 750, in process_event_queue
    if pipeline.manager.eventMatches(event, change):
  File "/usr/local/lib/python2.7/dist-packages/zuul/scheduler.py", line 956, in eventMatches
    if ef.matches(event, change):
  File "/usr/local/lib/python2.7/dist-packages/zuul/model.py", line 1077, in matches
    if (normalizeCategory(approval['description']) != k or
KeyError: 'description'
[...]