In any suit, action or proceeding involving the validity or enforceability of any bond issued under this article or the security therefor, any such bond reciting in substance that it has been issued by Montgomery County in connection with an urban renewal project, as herein defined, shall be conclusively deemed to have been issued for such purpose and such project shall be conclusively deemed to have been planned, located and carried out in accordance with the provisions of this article. (Mont. Co. Code 1965, § 26-13; 1961, ch. 821, § 1.)