[Buildbot] #3577: remove "repo" command from worker

[Buildbot trac]

#3577: remove "repo" command from worker
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Reporter:  rutsky     |      Owner:
    Type:  undecided  |     Status:  new
Priority:  major      |  Milestone:  0.9.0
 Version:  master     |   Keywords:
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 [https://github.com/buildbot/buildbot/blob/master/worker/buildbot_worker/commands/registry.py#L24
 repo command ] is not used anymore in Buildbot master and should be
 removed.

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Ticket URL: <http://trac.buildbot.net/ticket/3577>
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