Retirement of the capital stock of a domestic stock insurance company and the payment to the holders of such stock of its value under a plan for the mutualization of such company shall not constitute a sale of such stock within the prohibition of section 44-320; nor shall a contract to reinsure or assume the risks and business of another insurance company through reinsurance or consolidation as provided for by sections 44-224.01 to 44-224.10, be deemed to be either a sale or purchase of property within the prohibition of section 44-320.