(2) There shall be, if necessary, a relisting, reassessment and a relevy of the proper tax in the manner and by the person authorized by law to list property and levy and assess a tax. The relisting, reassessment and relevying shall take place within five years from the date the tax would have been delinquent if the property had been properly listed, assessed and tax levied thereon. If the question is raised in the courts as to the legality of such tax, the five years shall not commence to run until the question is finally determined by the courts.