When submitting the Order Items inline form on an Order edit form, the Unit Price shown on the inline form doesn't revert to default if the "Override the unit price" checkbox is unchecked.
Steps to reproduce:
Edit an order with an order item that has a default price "A".
Click Edit on the order item, check the "Override the unit price" checkbox, set a new price "B", and click "Update order item".
The Order Items inline form is submitted and the unit price is correctly shown as "B".
Click Edit the order item, uncheck the "Override the unit price" checkbox, and click "Update order item".
The Order Items inline form is submitted and the unit price is incorrectly shown as "B" instead of "A".