modules: use sockaddr_storage for socket address

sockaddr_in only works for ipv4, for ipv6, the address will be truncated
and then cause a stack overread in inet_ntop.

src/modules/module-protocol-simple.c

@@ -576,7 +576,7 @@ on_connect(void *data, int fd, uint32_t mask)
 {
 	struct server *server = data;
 	struct impl *impl = server->impl;
-	struct sockaddr_in addr;
+	struct sockaddr_storage addr;
 	socklen_t addrlen;
 	int client_fd, val;
 	struct client *client = NULL;