No contest, action or proceedings to question the validity or legality of any resolutions adopted or proceedings had under the provision of this Sub-part shall be begun in any court by any person for any cause whatsoever, after the expiration of thirty days from the date when the resolution was adopted, or proceedings had, and after such time the regularity of such resolution or proceeding shall be conclusively presumed.

Added by Acts 1956, No. 517, §1.