FreeSWITCH-FS-6836

Merge pull request #456 in FS/freeswitch from ~JMESQUITA/freeswitch:bugfix/FS-8089-pop-out-member-list-on-conference to master

* commit 'b7fa8f3347bbc1b52412db185e23ebf66e38abe6':
  FS-8088 [verto_communicator] Call conference destroy upon hangup and on event destroy to properly unsub from events.