[FIX] account: remove default journal in cut-off

The journal in a cut-off has to be of type general. But there is an
issue at the moment where a default_journal_id would be provided in
the context (coming from the dashboard for example) and thus, fill
the journal in the cut-off wizard with a wrong value (vendor bill for
example).

This change make sure no default values are provided to the wizard.

closes odoo/odoo#87136

X-original-commit: 5b099bf6
Signed-off-by: Florian Gilbert <flg@odoo.com>
Signed-off-by: Nicolas Viseur <vin@odoo.com>