FreeSWITCH-FS-7447

Merge pull request #351 in FS/freeswitch from ~DRAGOS_OANCEA/freeswitch-dragos:rtcp_loss_fraction_codec_control-fix to master

* commit '18b47b8e781818e758bb0604b4b8e6ca2302497e':
  FS-7844: packet loss fraction fix when calculating loss average