Whenever prior to January first, one thousand nine hundred and twenty-four, pursuant to section five hundred and eight of the act, approved proved the eighteenth day of May, Anno Domini one thousand nine hundred and eleven (Pamphlet Laws, page three hundred and nine), entitled “An act to establish a public school system in the Commonwealth of Pennsylvania, together with the provisions by which it shall be administered, and prescribing penalties for the violation thereof; providing revenue to establish and maintain the same, and the method of collecting such revenue; and repealing all laws, general, special or local, or any parts thereof, that are or may be inconsistent therewith,” and its amendments, any school district of this Commonwealth shall have incurred a temporary debt or borrowed money, such indebtedness is hereby declared to have been validly incurred and such money lawfully borrowed, and the certificates of indebtedness or obligations issued therefor to be binding obligations upon such school district, notwithstanding that said certificates of indebtedness or obligations were not issued under the seal of the district, if any; were not properly attested by the president and secretary of the board of directors of such district; and that it does not appear from the minutes of such board of school directors or otherwise that the incurring of the said debt and the authority to execute the said certificates of indebtedness or other obligations had received the vote of not less than two-thirds of the members of such board of school directors; and that such school district had not provided for the payment of the same from its current revenue: Provided, however, That it appears from the report of the auditors of such school district or otherwise that the proceeds of the sale or discount of the said certificates of indebtedness or obligations so issued were received by the said school district or credited to its account: And provided further, That such certificates of indebtedness or obligations were signed by at least two officers of such board of school directors, and that the indebtedness of such school district, including such debt or money borrowed, did not constitute two per centum of the total valuation of the taxable property of such school district for school purposes therein: And provided further, That in all other respects the provisions of section five hundred and eight of the said act of May eighteenth, one thousand nine hundred and eleven and of the amendments thereto, were complied with.