reverted TreeBuilder

Author: pesektomas

src/DependencyInjection/Configuration.php

@@ -16,8 +16,13 @@ class Configuration implements ConfigurationInterface
      */
     public function getConfigTreeBuilder()
     {
-        $treeBuilder = new TreeBuilder('fp_js_form_validator');
-        $rootNode = $treeBuilder->getRootNode();
+        /*
+         * symfony 4.3 version
+         * $treeBuilder = new TreeBuilder('fp_js_form_validator');
+         * $rootNode = $treeBuilder->getRootNode();
+         */
+        $treeBuilder = new TreeBuilder();
+        $rootNode = $treeBuilder->root('fp_js_form_validator');
 
         /** @noinspection PhpUndefinedMethodInspection */
         $rootNode