make sure HTTP test uses HTTP only and doesn't get redirected

_test/tests/inc/httpclient_http_proxy.test.php

 <?php
 
 class httpclient_http_proxy_test extends DokuWikiTest {
-    protected $url = 'http://www.dokuwiki.org/README';
+    protected $url = 'http://test.dokuwiki.org/README';
 
     /**
      * @group internet