Fix a typo which caused a double free in chan_zap. This was discovered

by Juggie while attempting to load chan_zap. Apparently this would happen
if an error were encountered while trying to process zapata.conf.



git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@109802 65c4cc65-6c06-0410-ace0-fbb531ad65f3