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: http://svn.asterisk.org/svn/asterisk/trunk@396695 f38db490-d61c-443f-a65b-d21fe96a405b