minissdpd: Cosmetic changes
minissdpd: revert "listen on only 1 IPv4 if only 1 interface is specified"

because it prevents broadcast messages to be received
see 7ec7cec59e88bd5d2b346e704a4b96d03d0df5aa
and 6d379d54f5e5d3bb9457d167ee9dbe4a044566ca