Fixed extension clashes

src/ServicesProvider/ServicesProvider.php

@@ -50,7 +50,9 @@ class ServicesProvider
         $container->extend('view', function ($view, $c) {
             $twig = $view->getEnvironment();
 
-            $twig->addExtension(new IntlExtension());
+            if (!$twig->hasExtension('Twig\Extra\Intl\IntlExtension')) {
+                $twig->addExtension(new IntlExtension());
+            }
             $twig->addExtension(new FormatCronExtension($c));
 
             return $view;