Remove the vendor directory in .gitignore as these dependencies are needed for php-imap

plugins/php-imap/vendor/symfony/translation/IdentityTranslator.php

@@ -0,0 +1,26 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Translation;
+
+use Symfony\Contracts\Translation\LocaleAwareInterface;
+use Symfony\Contracts\Translation\TranslatorInterface;
+use Symfony\Contracts\Translation\TranslatorTrait;
+
+/**
+ * IdentityTranslator does not translate anything.
+ *
+ * @author Fabien Potencier <fabien@symfony.com>
+ */
+class IdentityTranslator implements TranslatorInterface, LocaleAwareInterface
+{
+    use TranslatorTrait;
+}