When editing a trade, the item that you traded away isn't in the dropdown

[kevinmook]

This means when you save the updated trade, it no longer traded away the item. I think this is because the dropdown is filtering to items you currently own so the traded item isn't in the list.

Steps to reproduce:

1. Have a character that has at least one magic item
2. Make a new trade and trade away that magic item
3. Save the trade
4. Go back and edit the trade - the magic item you traded away is not in the dropdown of magic items
5. If you save the trade, your character now has that magic item again

[kevinmook]

Looks like this is a dupe of #255, though this is a specific instance of what happens where that other issue is more general.

Feel free to close this issue if you want to track it on that other one, or keep this open if you prefer to keep track of them individually.