minor symfony#16566 [HttpFoundation] Fix undefined array $server (belka-ew)

This PR was submitted for the 2.8 branch but it was merged into the 2.3 branch instead (closes symfony#16566).

Discussion
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[HttpFoundation] Fix undefined array $server

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets |
| License       | MIT
| Doc PR        |

$server variable isn't defined in the test /src/Symfony/Component/HttpFoundation/Tests/RequestTest.php:RequestTest

Commits
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75aa6f6 Fix undefined array $server

Author: fabpot

src/Symfony/Component/HttpFoundation/Tests/RequestTest.php

@@ -570,7 +570,7 @@ public function testGetUserInfo()
     {
         $request = new Request();
 
-        $server['PHP_AUTH_USER'] = 'fabien';
+        $server = array('PHP_AUTH_USER' => 'fabien');
         $request->initialize(array(), array(), array(), array(), array(), $server);
         $this->assertEquals('fabien', $request->getUserInfo());