Merged revisions 208587 via svnmerge from

https://origsvn.digium.com/svn/asterisk/branches/1.4

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  r208587 | mmichelson | 2009-07-24 13:26:50 -0500 (Fri, 24 Jul 2009) | 10 lines
  
  Only send a BYE when hanging up a channel that is up.
  
  For cases where Asterisk sends an INVITE and receives a non 2XX final
  response, Asterisk would follow the INVITE transaction by immediately
  sending a BYE, which was unnecessary.
  
  (closes issue #14575)
  Reported by: chris-mac
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git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@208588 65c4cc65-6c06-0410-ace0-fbb531ad65f3