AuditFilterType fix validation errors

Form/Type/AuditFilterType.php

@@ -39,7 +39,6 @@ class AuditFilterType extends AbstractType
                 ))
                 ->add('users', ChoiceType::class, array(
                     'choices' => $this->auditDataService->getRevisionUsers(),
-                    'empty_data' => '',
                     'required' => false,
                     'multiple' => true,
                     'choice_translation_domain' => false,
@@ -50,7 +49,6 @@ class AuditFilterType extends AbstractType
                         'UPD' => 'UPD',
                         'DEL' => 'DEL',
                     ),
-                    'empty_data' => '',
                     'required' => false,
                     'multiple' => true,
                     'choice_translation_domain' => false,