Update symfony validator

[MAILPOET-3241]

lib/Doctrine/Validator/ValidatorFactory.php

@@ -19,6 +19,12 @@ class ValidatorFactory {
 
   public function createValidator() {
     $builder = Validation::createValidatorBuilder();
+    // we need to use our own translator here.
+    // If we let the default translator to be used in the builder it uses an anonymous class and that is a problem
+    // All integration tests would fail with: [Exception] Serialization of 'class@anonymous' is not allowed
+    $translator = new Translator();
+    $translator->setLocale('en');
+    $builder->setTranslator($translator);
 
     // annotation reader exists only in dev environment, on production cache is pre-generated
     $annotationReader = $this->annotationReaderProvider->getAnnotationReader();