rem: return challenge(_msg, (str*)_realm, (int)_qop, 401, MESSAGE_401, WWW_AUTH_CHALLENGE);
add: return challenge(_msg, (str*)_realm, (int)(long)_qop, 401, MESSAGE_401, WWW_AUTH_CHALLENGE);
context: int www_challenge(struct sip_msg* _msg, char* _realm, char* _qop){	return challenge(_msg, (str*)_realm, (int)_qop, 401, MESSAGE_401, WWW_AUTH_CHALLENGE);}