[Testing] Fixed a minor formatting issue

Author: javiereguiluz

testing.rst

@@ -699,7 +699,7 @@ given text (or the first clickable image with that ``alt`` attribute)::
 
 If you need access to the :class:`Symfony\\Component\\DomCrawler\\Link` object
 that provides helpful methods specific to links (such as ``getMethod()`` and
-``getUri()``), use the ``selectLink()`` method instead:
+``getUri()``), use the ``selectLink()`` method instead::
 
     $client = static::createClient();
     $crawler = $client->request('GET', '/post/hello-world');