Ruby

• ext/socket/lib/socket.rb (Socket.udp_server_sockets): call the block
  if given. close the sockets when the block exits.
  (Socket.udp_server_loop): use udp_server_sockets in block form.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@22238 b2dd03c8-39d4-4d8f-98ff-823fe69b080e