FreeSWITCH

Merge pull request #200 in FS/freeswitch from ~SJTHOMASON/freeswitch:bugfix/FS-7192-expires-header-included-in-gateway to master

* commit '54f16398310846a6b793491d21778e0961b48712':
  FS-7192: [mod_sofia] do not include Expires header in INVITEs responding to a auth challenge