Revert "merged branch trompette/patch-1 (PR #1761)"

This reverts commit 8e3b9c334d38b644af70e86d9598371869831d95, reversing
changes made to 61f02902fea4b415fbf212f25eee93251a5e4b8f.

tests/Symfony/Tests/Component/HttpFoundation/RequestMatcherTest.php

@@ -71,7 +71,7 @@ class RequestMatcherTest extends \PHPUnit_Framework_TestCase
 
     public function testAnIpv6WithOptionDisabledIpv6()
     {
-        if (!defined('AF_INET6')) {
+        if (defined('AF_INET6')) {
             $this->markTestSkipped('Only works when PHP is compiled with the option "disable-ipv6".');
         }