[Buildbot] #3484: update screenshots in firstrun tutorial

[Buildbot trac]

#3484: update screenshots in firstrun tutorial
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Reporter:  rutsky     |      Owner:
    Type:  undecided  |     Status:  new
Priority:  major      |  Milestone:  undecided
 Version:  0.9.0b7    |   Keywords:
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Ticket URL: <http://trac.buildbot.net/ticket/3484>
Buildbot <http://buildbot.net/>
Buildbot: build/test automation