MEETME_INFO should not return a literal error message to the dialplan.

(closes issue #15450)
 Reported by: JimVanM
 Patches: 
       meetmeinfopatch.diff.txt uploaded by dbrooks (license 790)
 Tested by: JimVanM


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@228191 65c4cc65-6c06-0410-ace0-fbb531ad65f3