menu descriptor must be only present in main

If we add the same menu descriptor 
the additionnal menu are added on the second, not the main
I propose to suppress it OR change "customers_bills" as "customers_bills_list" who allow to add some menu as sub-menu

htdocs/core/menus/standard/eldy.lib.php

@@ -802,7 +802,7 @@ function print_left_eldy_menu($db,$menu_array_before,$menu_array_after,&$tabMenu
 				$langs->load("bills");
 				$newmenu->add("/compta/facture/list.php?leftmenu=customers_bills",$langs->trans("BillsCustomers"),0,$user->rights->facture->lire, '', $mainmenu, 'customers_bills');
 				$newmenu->add("/compta/facture/card.php?action=create",$langs->trans("NewBill"),1,$user->rights->facture->creer);
-				$newmenu->add("/compta/facture/list.php?leftmenu=customers_bills",$langs->trans("List"),1,$user->rights->facture->lire, '', $mainmenu, 'customers_bills');
+				$newmenu->add("/compta/facture/list.php?leftmenu=customers_bills",$langs->trans("List"),1,$user->rights->facture->lire);
 
 				if ($usemenuhider || empty($leftmenu) || preg_match('/customers_bills/', $leftmenu))
 				{
@@ -830,7 +830,7 @@ function print_left_eldy_menu($db,$menu_array_before,$menu_array_after,&$tabMenu
 				$langs->load("bills");
 				$newmenu->add("/fourn/facture/list.php?leftmenu=suppliers_bills", $langs->trans("BillsSuppliers"),0,$user->rights->fournisseur->facture->lire, '', $mainmenu, 'suppliers_bills');
 				$newmenu->add("/fourn/facture/card.php?action=create",$langs->trans("NewBill"),1,$user->rights->fournisseur->facture->creer);
-				$newmenu->add("/fourn/facture/list.php?leftmenu=suppliers_bills", $langs->trans("List"),1,$user->rights->fournisseur->facture->lire, '', $mainmenu, 'suppliers_bills');
+				$newmenu->add("/fourn/facture/list.php?leftmenu=suppliers_bills", $langs->trans("List"),1,$user->rights->fournisseur->facture->lire);
 
 				if ($usemenuhider || empty($leftmenu) || preg_match('/suppliers_bills/', $leftmenu)) {
 					$newmenu->add("/fourn/facture/list.php?leftmenu=suppliers_bills_draft&search_status=0", $langs->trans("BillShortStatusDraft"),2,$user->rights->fournisseur->facture->lire, '', $mainmenu, 'suppliers_bills_draft');