ensure that 'zap show status' always generates output, even when there are no...

ensure that 'zap show status' always generates output, even when there are no interfaces present (bug #3585)


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@5996 65c4cc65-6c06-0410-ace0-fbb531ad65f3