Sanity check code for an extended failure in trying to obtain a channel lock...

 Sanity check code for an extended failure in trying to obtain a channel lock that may have been obtained elsewhere. Prevents the monitor thread of the SIP module from going into an infinite loop, effectively, breaking SIP until you restart Asterisk or the mutex is unlocked, whichever comes first.



git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@29735 65c4cc65-6c06-0410-ace0-fbb531ad65f3