All cities of the second class in the state of Kansas which have heretofore or may hereafter adopt the commission form of government, are hereby authorized and empowered to refund all its outstanding indebtedness existing and outstanding at the time of the adoption and up to the time of the inauguration of the commission form of government by such city, by issuing refunding bonds thereof. Such refunding bonds shall be issued and the former indebtedness shall be canceled as provided by law.