FreeSWITCH

Merge pull request #246 in FS/freeswitch from ~ITALOROSSI/freeswitch:bugfix/FS-7464-callcenter-cannot-play-us-ring-tone_stream to master

* commit '1bc241922e3136dda8067723a4d4c9ebdd51f101':
  FS-7464 mod_callcenter moh-sound needs to be expanded when containing variables.