rem: snprintf(url->user, sizeof(url->user), user);
add: url->user = STRDUP(user);
context: void opn_url_set_client(OpnUrl *url, char *user, in_addr_t ip,                        in_port_t port){	assert(url);	url->client.ip = ip;	url->client.port = port;	snprintf(url->user, sizeof(url->user), user);}