[FIX] account: fix auto-reconciliation with multiple currencies

- Create a Bank journal [BNK2] with foreign currency
- Create a reconciliation model:
  * Type: Rule to suggest counterpart entry
  * Amount Type: Paid/Received
  * Auto-validate: True
  * Journals: [BNK2]
  * Label: Contains [Test]
  * Partner Is Set: False
  * Counterpart Entries:
    - Account: select an expense account
    - Amount Type: Percentage of statement line
    - Amount: 100
    - Taxes: add the 15% purchase tax
    - Tax Included in Price: True
- create a bank statement on [BNK2] with reference [Test]
- post that statement and reconcile it

Look at the resulting journal entries.
The tax amount is incorrect, and we will have an open balance.

This occurs after bc0bfde1
In version 14 counterpart amounts are by default in company currency so
we should force the currency after retrieving writeoff vals

opw-3068801

closes odoo/odoo#108487

Signed-off-by: Laurent Smet <las@odoo.com>