Notwithstanding any more general or special law respecting sale or conveyance of real estate now or hereafter owned by cities and villages in force and effect in this state, the governing bodies of cities and villages are empowered to direct their proper officers to execute deeds for conveyance of any real estate of such cities or villages without consideration to the State of Nebraska for the construction of state armory buildings on such real estate. Such construction shall be made without cost to such cities or villages.