§ 524. Validation. All proceedings, acts and things undertaken, performed or done by any municipality or the state division of housing pursuant to sections seventy-two-k, seventy-two-l, seventy-two-m, seventy-two-n and seventy-two-o of the general municipal law or done with reference thereto are hereby validated, ratified, confirmed, approved and declared legal in all respects, notwithstanding any want of statutory authority or any defect or irregularity in such acts or proceedings.