bug #3537 Add missing variable assignment (colinodell)

This PR was submitted for the 2.2 branch but it was merged into the 2.3 branch instead (closes #3537).

Discussion
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Add missing variable assignment

Line 41 made use of $crawler which wasn't defined.

Commits
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8f41c15 Add missing variable assignment

cookbook/testing/simulating_authentication.rst

@@ -35,7 +35,7 @@ with a request. The following example demonstrates this technique::
         {
             $this->logIn();
 
-            $this->client->request('GET', '/demo/secured/hello/Fabien');
+            $crawler = $this->client->request('GET', '/demo/secured/hello/Fabien');
 
             $this->assertTrue($this->client->getResponse()->isSuccessful());
             $this->assertGreaterThan(0, $crawler->filter('html:contains("Hello Fabien")')->count());