This act shall not apply to or validate any indebtedness of any township, or to any note, certificate, or other obligation, which violates any restriction imposed by any provision of the Constitution of this Commonwealth, neither shall it apply to or validate any indebtedness which shall have been declared invalid by the final judgment of any court of competent jurisdiction in a suit or action to which the holders of any such note, certificate, or other obligation were parties.
53 P.S. § 70105