Any railroad company incorporated by the laws of this state may at any time reduce the amount of its capital or common stock by a vote of three-fifths in interest of all the stock of such company to be affected thereby, at a stockholders’ meeting, called in conformity to the bylaws of such company; and if so voted for, said capital stock may be reduced upon the plan in detail thus submitted to the stockholders; provided, that such reduction shall be so made as to affect the interest of all stockholders alike; provided, that nothing in this section shall be so construed as to permit the reduction of the capital stock of any company below the minimum amount prescribed by law.