No bonds in excess of fifteen percentum of the assessed valuation of tangible property in such city shall be issued under the authority of Kan. Stat. Ann. §§ 12-801 and 12-802, and such bonds may be issued by any city without regard to the statutory limitations of bonded indebtedness of such city and shall not be included in computing the total bonded indebtedness of such city within the meaning of other statutes limiting such bonded indebtedness.