ServiceBrowser: don't browse interfaces that don't have multicast enabled (#9)
ServiceBrowser: don't browse interfaces that don't have multicast enabled (#9)

Setting multicast related socket options on interfaces that don't have
multicast enabled causes exceptions: https://github.com/tmds/Tmds.MDns/issues/8.

MDns needs multicast to work so we skip interfaces which don't have multicast
enabled.
tmds/Tmds.MDns