[FIX] l10n_sg: tax report adapted to changes in generic P&L

OPINC (Operating Income) has been replaced by REV (Revenue), still filtering the same journal items ([('account_id.account_type', '=', 'income')])

See odoo/enterprise#69959

closes odoo#180243

Related: odoo/upgrade#6508
Signed-off-by: Quentin De Paoli (qdp) <[email protected]>

Author: qdp-odoo

addons/l10n_sg/data/account_tax_report_data.xml

@@ -180,7 +180,7 @@
                             <record id="account_tax_report_line_revenues_accounting_period_formula" model="account.report.expression">
                                 <field name="label">balance</field>
                                 <field name="engine">aggregation</field>
-                                <field name="formula">OPINC.balance</field>
+                                <field name="formula">REV.balance</field>
                                 <field name="subformula">cross_report</field>
                             </record>
                         </field>