[FIX] stock: avoid traceback when owner on picking and transfer more.

If you create a picking, with an owner, for qty x, and confirm it.
Next transfer x+1, it will raise a traceback 'cannot adapt res.partner'

Now, we pass the id, and not the browse record.

This commit closes #12978

addons/stock/stock.py

@@ -1373,7 +1373,7 @@ class stock_picking(osv.osv):
             'product_uom_qty': qty,
             'name': _('Extra Move: ') + name,
             'state': 'draft',
-            'restrict_partner_id': op.owner_id,
+            'restrict_partner_id': op.owner_id.id,
             'group_id': picking.group_id.id,
             }
         return res