Create server multicast socket. Socket will be joined to the multicast-group (same as it is
		specified in client configuration, same as client does)

		:param config: server configuration
		:return: socket.socket

def create_server_socket(self, config):
		""" Create server multicast socket. Socket will be joined to the multicast-group (same as it is
		specified in client configuration, same as client does)

		:param config: server configuration
		:return: socket.socket
		"""
		server_socket = WUDPNetworkNativeTransport.create_server_socket(self, config)

		group = socket.inet_aton(str(self.target_socket(config).address()))
		group_membership = struct.pack('4sL', group, socket.INADDR_ANY)
		server_socket.setsockopt(socket.IPPROTO_IP, socket.IP_ADD_MEMBERSHIP, group_membership)
		return server_socket