FreeSWITCH

Merge pull request #1759 in FS/freeswitch from ~DRAGOS_OANCEA/freeswitch-dragos:FS-11951 to master

* commit '54c589500925106ed05de3331d195a0a3cafa366':
  FS-11951: JB: rare crash in reading the chan var  (it maybe called without a session in some unit tests)