- Don't hangup because of failed re-invite. Go back to previous state.

- Keep RTP running during T.38 session
  We might improve the code to issue ast_rtp_stop if T.38 re-invite not fails
  later on in the code, but I don't see many reasons to.


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@47510 65c4cc65-6c06-0410-ace0-fbb531ad65f3