[FIX] l10n_ch: traceback when installing module

Getting traceback when installing the l10n_ch module.

In the form view of journal, the field "l10n_ch_postal" is added using the xpath.
However the field provided in the expression of xpath('bank_acc_number') doesn't
seem to exist anymore in the form view of account journal.

Hence, it is replaced with the existing field('bank_account_id') in form view
of journal.

task-1999654

closes odoo/odoo#33702

Signed-off-by: Quentin De Paoli (qdp) <qdp@openerp.com>

addons/l10n_ch/views/res_bank_view.xml

@@ -29,7 +29,7 @@
             <field name="model">account.journal</field>
             <field name="inherit_id" ref="account.view_account_journal_form"/>
             <field name="arch" type="xml">
-                <xpath expr="//field[@name='bank_acc_number']" position="after">
+                <xpath expr="//field[@name='bank_account_id']" position="after">
                     <field name="l10n_ch_postal" attrs="{'invisible': [('type', 'not in', ['bank', 'cash'])]}"/>
                 </xpath>
             </field>