Fix random segfault issue when loading chan_zap. Trying to access a...

Fix random segfault issue when loading chan_zap. Trying to access a configuration structure that has already been destroyed is bad, mmmk?


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@80023 65c4cc65-6c06-0410-ace0-fbb531ad65f3