Set origin to null when clone a stock move
In stock.move model has not copy() method to reset origin field to null when duplicate a shipment
Scenario:
1- Install stock_consignment module and configure locations to create invoice lines.
2- Create a shipment internal and assign => create account invoice lines from stock moves.
3- Duplicate the shipment => stock.move has the origin of the previous stock.move (account.invoice.line)
4- Assign duplicated shipment => not generate new invoice lines because has an origin