Any county treasurer who fails to make settlement with the commissioner of management and budget within 15 days of the time prescribed by law, shall forfeit and pay the sum of $100, in addition to the penalties provided in section 385.21, to be recovered in a civil action, which forfeiture shall be paid into the state treasury to the credit of the general fund. The commissioner of management and budget, for good cause shown, may remit the penalty at any time before an action is commenced.