[FIX] hr_timesheet_invoice: fully qualify grouped fields in SQL view

Avoids name collisions when custom columns are involved.

Closes #11743

addons/hr_timesheet_invoice/report/report_analytic.py

@@ -101,7 +101,7 @@ class report_account_analytic_line_to_invoice(osv.osv):
                 WHERE
                     (invoice_id IS NULL) and (to_invoice IS NOT NULL)
                 GROUP BY
-                    to_char(l.date, 'YYYY'), to_char(l.date,'MM'), product_id, product_uom_id, account_id
+                    to_char(l.date, 'YYYY'), to_char(l.date,'MM'), l.product_id, l.product_uom_id, l.account_id
             )
         """)