FreeSWITCH-FS-8767

Merge pull request #571 in FS/freeswitch from ~VIPKILLA/fs-8392:master to master

* commit 'e6ae2e9becd51fe1ea4141d381ba2006bac823f3':
  FS-8392: change rtpmap payload to a number in dynamic range to allow both H263 and H263+ to be offered