chan_sip: Fix so asterisk won't send reINVITE after a BYE.

chan_sip: Fix so asterisk won't send reINVITE after a BYE.

After a reINVITE glare situation, Asterisk would re-send the reINVITE
even though the call had been hung up in the mean time.  This patch
unschedules the reinvite when handling the BYE.

ASTERISK-22791 #close
Reported by: Paolo Compagnini
Tested by: Paolo Compagnini

Review: https://reviewboard.asterisk.org/r/4056/
(testcase is in review r4055)
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Merged revisions 425296 from http://svn.asterisk.org/svn/asterisk/branches/1.8
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Merged revisions 425297 from http://svn.asterisk.org/svn/asterisk/branches/11
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Merged revisions 425298 from http://svn.asterisk.org/svn/asterisk/branches/12
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Merged revisions 425299 from http://svn.asterisk.org/svn/asterisk/branches/13

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@425300 65c4cc65-6c06-0410-ace0-fbb531ad65f3