FreeSWITCH-FS-8767

Merge pull request #265 in FS/freeswitch from ~DRAGOS_OANCEA/freeswitch-dragos:codec2_fix_encoded_data_len to master

* commit '83923660577cac053deeac3b9901df45e0cf8487':
  Fixed encoded_data_len for MODE 2400, it should be 6 bytes. Also replaced 2550 bps bitrate (obsoleted operation mode) by 2400