FreeSWITCH

Merge pull request #534 in FS/freeswitch from ~COREY BURKE/freeswitch:bugfix/FS-8284-opus-asks-callee-to-use-dtx-even to master

* commit '0641315ef6dd8c612de1c7ffac06df6473ec2e4f':
  Use use-dtx setting from config in request to callee.