Fix for UPnP listener not listening, which erroneously caused PMS to
only detect devices when an ALIVE message was sent.

Apparently forcing the network interface on a MulticastSocket created
by port is okay with Java 1.6.0_45 on Mac OSX (it was removed for that
reason in 98c85bce).
Merge branch 'master' of github.com:ps3mediaserver/ps3mediaserver