app_bridgewait: Inhibit local channel optimizations to the bridge.

Holding bridges can allow local channel move/swap optimization to the
bridge.  However, we cannot allow it for the BridgeWait holding bridge
because the call will lose the channel roles and dialplan location as a
result.


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@396695 65c4cc65-6c06-0410-ace0-fbb531ad65f3