Currency printed when amount not filled in

[beardhatcode]

Reproduction steps

1. Add a transaction but only fill in the amount in the first box (leave the second amount one empty)

2. notice that the second box has a prefilled value
   

3. Click save (:white_check_mark: )

Expected behaviour

2023-09-14 test | test
    test amount filled in                42 EUR
    amount not filled in                -42 EUR

or

2023-09-14 test | test
    test amount filled in                42 EUR
    amount not filled in  

Actual behaviour

2023-09-14 test | test
    test amount filled in                42 EUR
    amount not filled in                EUR

System information

I have currency on the right but the error is also there with currency on the left.

Version: v0.1.1