[FIX] l10n_din5008_repair: remove reference to deleted field

Steps to reproduce
------------------
* install `l10n_din5008_repair`
* set the document layout to din5008
* create a Repair order and attempt to print it

You should be met with a traceback.

opw-3718479

closes odoo/odoo#155597

X-original-commit: aca5b96a7ffd9811d8b90a04686eeeadc55156f5
Signed-off-by: Séna Serge Nshimiyimana (sesn) <sesn@odoo.com>

addons/l10n_din5008_repair/models/repair.py

@@ -15,8 +15,6 @@ class RepairOrder(models.Model):
                 data.append((_("Product to Repair"), record.product_id.name))
             if record.lot_id:
                 data.append((_("Lot/Serial Number"), record.lot_id.name))
-            if record.guarantee_limit:
-                data.append((_("Warranty"), format_date(self.env, record.guarantee_limit)))
             data.append((_("Printing Date"), format_date(self.env, fields.Date.today())))
 
     def _compute_l10n_din5008_document_title(self):