[FrameworkBundle|TwigBundle] update functional tests configuration files to not use deprecated config keys anymore.

Author: Hugo Hamon

DependencyInjection/Configuration.php

@@ -49,13 +49,21 @@ public function getConfigTreeBuilder()
     private function addFormSection(ArrayNodeDefinition $rootNode)
     {
         $rootNode
+            // Check deprecation before the config is processed to ensure
+            // the setting has been explicitly defined in a configuration file.
+            ->beforeNormalization()
+                ->ifTrue(function ($v) { return isset($v['form']['resources']); })
+                ->then(function ($v) {
+                    trigger_error('The twig.form.resources configuration key is deprecated since version 2.6 and will be removed in 3.0. Use the twig.form_themes configuration key instead.', E_USER_DEPRECATED);
+
+                    return $v;
+                })
+            ->end()
             ->validate()
                 ->ifTrue(function ($v) {
                     return count($v['form']['resources']) > 0;
                 })
                 ->then(function ($v) {
-                    trigger_error('The twig.form.resources configuration key is deprecated since version 2.6 and will be removed in 3.0. Use the twig.form_themes configuration key instead.', E_USER_DEPRECATED);
-
                     $v['form_themes'] = array_values(array_unique(array_merge($v['form']['resources'], $v['form_themes'])));
 
                     return $v;