When using a socket as a FILE *, the stdio functions will sometimes try to do

When using a socket as a FILE *, the stdio functions will sometimes try to do
an fseek() on the stream, which is an invalid operation for a socket.  Turning
off buffering explicitly lets the stdio functions know they cannot do this,
thus avoiding a potential error.
(closes issue #14400)
 Reported by: fnordian
 Patches:
       tcptls.patch uploaded by fnordian (license 110)

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@173458 65c4cc65-6c06-0410-ace0-fbb531ad65f3