rem: static int xl_get_reason(struct sip_msg *msg, str *res)
add: static int xl_get_reason(struct sip_msg *msg, str *res, str *hp, int hi)
context: static int xl_get_reason(struct sip_msg *msg, str *res){	if(msg==NULL || res==NULL)		return -1;	if(msg->first_line.type == SIP_REPLY)	{		res->s = msg->first_line.u.reply.reason.s;		res->len = msg->first_line.u.reply.reason.len;			}	else		return xl_get_null(msg, res);		return 0;}