Merge branch '4.4'

* 4.4:
  cs fix
  [Mailer] Check email validity before opening an SMTP connection

Author: nicolas-grekas

Tests/AbstractBrowserTest.php

@@ -12,12 +12,9 @@
 namespace Symfony\Component\BrowserKit\Tests;
 
 use PHPUnit\Framework\TestCase;
-use Symfony\Component\BrowserKit\AbstractBrowser;
 use Symfony\Component\BrowserKit\CookieJar;
 use Symfony\Component\BrowserKit\History;
 use Symfony\Component\BrowserKit\Response;
-use Symfony\Component\DomCrawler\Crawler;
-use Symfony\Component\DomCrawler\Form as DomCrawlerForm;
 
 class AbstractBrowserTest extends TestCase
 {