Purchasers of land sold for nonpayment of assessments for opening and making roads have no claim against the county for any defect in the title under such sale, notwithstanding any irregularities in the proceedings or failure to comply with the law under which the sales were made. Deeds given pursuant to sales made for nonpayment of such assessments vest in the grantee the title of the county to the lands sold, subject to the conditions of sale, and no more.