Fix wrong attribute

coin/billing/models.py

@@ -283,7 +283,7 @@ class Invoice(models.Model):
             **kwargs)
 
         # Sauvegarde en base la date du dernier envoi de mail de relance
-        self.date_last_call_for_membership_fees_email = timezone.now()
+        self.date_last_reminder_email = timezone.now()
         self.save()
         return True