fix: submit BusPro nationality token for applicant

src/Form/BookingApplicantType.php

@@ -4,11 +4,11 @@ declare(strict_types=1);
 
 namespace App\Form;
 
+use App\BusProNet\Form\CountryType;
 use App\Form\Model\ParticipantDto;
 use Symfony\Component\Form\AbstractType;
 use Symfony\Component\Form\Extension\Core\Type\BirthdayType;
 use Symfony\Component\Form\Extension\Core\Type\ChoiceType;
-use Symfony\Component\Form\Extension\Core\Type\CountryType;
 use Symfony\Component\Form\Extension\Core\Type\EmailType;
 use Symfony\Component\Form\Extension\Core\Type\TextType;
 use Symfony\Component\Form\FormBuilderInterface;
@@ -53,6 +53,8 @@ class BookingApplicantType extends AbstractType
             ->add('nationality', CountryType::class, [
                 'label' => 'Nationalität',
                 'required' => true,
+                'property' => 'nationality',
+                'placeholder' => 'Bitte auswählen...',
                 'preferred_choices' => ['D', 'A', 'CH'],
             ])
             ->add('dateOfBirth', BirthdayType::class, [