[18.0][FIX] fix formatLand declaration

Author: rdualsam

purchase_usability_akretion/models/purchase_order.py

@@ -3,7 +3,7 @@
 # License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).
 
 from odoo import api, fields, models
-from odoo.tools.misc import format_amount
+from odoo.tools import formatLang
 
 
 class PurchaseOrder(models.Model):