If it appears to the satisfaction of the board of supervisors that the county is justly indebted to any person for money received into the treasury of the county and used by the county, for an indebtedness which at the time of its creation was not authorized by law, it shall by ordinance declare that the county is justly indebted to the person named in the ordinance in a sum stated therein, and that the question of issuing bonds in the sum stated, for the purpose of paying the debt shall be submitted to a vote of the voters of the county.