Small error in the T.140 RTP port verbose log.

(closes issue #16988)
Reported by: frawd
Patches: 
      chan_sip_sdp_verbose_fix.diff uploaded by frawd (license 610)
Tested by: russell

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@258934 65c4cc65-6c06-0410-ace0-fbb531ad65f3