FreeSWITCH-FS-6836

Merge pull request #859 in FS/freeswitch from ~SJTHOMASON/freeswitch:bugfix/FS-9183-call-with-t.38-reinvite-fails-after to master

* commit '5b71dffb8004c6e7045afeaf42c6a785c7496975':
  FS-9183: [mod_sofia] Handle 415 Unsupported Media Type as 488