fix: use correct country tokens

src/Form/AddressType.php

@@ -35,7 +35,7 @@ class AddressType extends AbstractType
                 'label' => 'Land',
                 'property' => 'country',
                 'required' => $options['required'],
-                'preferred_choices' => ['DE', 'AT', 'CH'],
+                'preferred_choices' => ['D', 'A', 'CH'],
             ]);
     }