[Buildbot] #2997: Fix typo in reverse DNS

[Buildbot trac]

#2997: Fix typo in reverse DNS
-------------------+-------------------------------
Reporter:  dustin  |      Owner:
    Type:  task    |     Status:  new
Priority:  major   |  Milestone:  sys - on-bb-infra
 Version:  0.8.9   |   Keywords:
-------------------+-------------------------------
 Missing `.`:

 {{{
 242.10.211.140.in-addr.arpa is an alias for 242.128-255.10.211.140.in-
 addr.arpa.
 242.128-255.10.211.140.in-addr.arpa domain name pointer
 bot.buildbot.net.128-255.10.211.140.in-addr.arpa.
 }}}

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Ticket URL: <http://trac.buildbot.net/ticket/2997>
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