Add support for allowing a native bridge to happen when the L option is...

Add support for allowing a native bridge to happen when the L option is enabled. The RTP bridging could already handle this, it just needed to be enabled in the main bridging code.
(issue #10647)
Reported by: samdell3


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@103314 65c4cc65-6c06-0410-ace0-fbb531ad65f3