Typehint array for config

Even if configuration is ArrayObject it is casted
to an array after retrieval, so we can have here typehint.

Author: michalbundyra

src/Container/ApplicationFactory.php

@@ -515,10 +515,10 @@ private function marshalNoopFinalHandler(ContainerInterface $container)
      * Create default FinalHandler with options configured under the key final_handler.options.
      *
      * @param ContainerInterface $container
-     * @param array|\ArrayObject $config
+     * @param array $config
      * @return callable|FinalHandler
      */
-    private function marshalLegacyFinalHandler(ContainerInterface $container, $config)
+    private function marshalLegacyFinalHandler(ContainerInterface $container, array $config)
     {
         if ($container->has('Zend\Expressive\FinalHandler')) {
             return $container->get('Zend\Expressive\FinalHandler');