MailWindow: Fix crash when using Button in Leseabschluss

Elwig/Windows/MailWindow.xaml.cs

@@ -954,7 +954,7 @@ namespace Elwig.Windows {
             AvaiableDocumentsList.SelectedIndex = 1;
             if (AvaiableDocumentsList.SelectedItem is not string s || SelectedDocs.Any(d => d.Type == DocType.DeliveryConfirmation))
                 return;
-            SelectedDocs.Add(new(DocType.DeliveryConfirmation, s, (Year, DocumentNonDeliverersInput.IsChecked == true)));
+            SelectedDocs.Add(new(DocType.DeliveryConfirmation, s, Year));
             SelectedDocumentsList.SelectedIndex = SelectedDocs.Count - 1;
             RecipientsDeliveryMembersInput.IsChecked = true;
         }