No such sale shall be held invalid or be set aside by reason of any defect in the notice thereof, or in the publication or service of such notice, or in the proceedings of the officer making the sale, unless the action in which the validity of such sale is called in question be commenced, or the defense alleging its invalidity be interposed, with reasonable diligence, and not later than five years after the date of such sale; provided that persons under disability to sue when such sale was made by reason of being minors, persons who lack the mental capacity to make decisions, persons with a developmental disability, or persons in captivity or in any country with which the United States is at war, may commence such action or interpose such defense at any time within five years after the removal of such disability.