“Provided that where it is proved to the satisfaction of the Magistrate that the defendant has contributed to the maintenance of the child, or has since the birth of the child cohabited with its mother as man and wife, then a complaint may be made and summons issued at any time after the expiration of the said six years, if within the six months immediately preceding the date of the complaint the defendant has made any payment towards the maintenance of the child or has so cohabited with its mother.”