Fix normalizer not being prefixed correctly

[MAILPOET-3105]

prefixer/fix-symfony-polyfill.php

@@ -0,0 +1,11 @@
+<?php
+
+// throw exception if anything fails
+set_error_handler(function ($severity, $message, $file, $line) {
+  throw new ErrorException($message, 0, $severity, $file, $line);
+});
+
+$file = __DIR__ . '/../vendor-prefixed/symfony/polyfill-intl-idn/Idn.php';
+$data = file_get_contents($file);
+$data = str_replace('use Normalizer;', 'use MailPoetVendor\\Normalizer;', $data);
+file_put_contents($file, $data);