91.550.  Referendum on sale of municipal utility by third class city. — Before any city of the third class shall sell or dispose of, in any way, or abandon or cease to operate any electric light plant, waterworks plant, gas plant, street railway or any other public utility which may be owned by it, it shall first submit the proposition for such sale or disposition or abandonment or ceasing to operate, by ordinance, to the voters of said city and it shall require a majority of the votes cast to be in favor of the proposition before any authority shall exist for such sale, disposition, abandonment or ceasing to operate.