ยง 6217. Additional undertaking to carrier garnishee. A garnishee who is a common carrier may transport or deliver property actually loaded on a conveyance, notwithstanding the service upon him of an order of attachment, if it was loaded without reason to believe that an order of attachment affecting the property had been granted, unless the plaintiff gives an undertaking in an amount fixed by the court, that the plaintiff shall pay any such carrier all expenses and damages which may be incurred for unloading the property and for detention of the conveyance necessary for that purpose.