Fix borked test case

Setting `CURLOPT_STDERR` can trigger a warning, what causes the test to
be marked as borked as of commit e49593a[1].  To avoid this, we silence
the `curl_setopt()` call.

[1] <http://git.php.net/?p=php-src.git;a=commit;h=e49593a7c3159a5673ce74b4e5133f1264dc313f>

Author: cmb69

ext/standard/tests/file/bug52820.phpt

@@ -10,7 +10,7 @@ if (!extension_loaded("curl")) exit("skip curl extension not loaded");
 $handle=curl_init('http://127.0.0.1:37349/');
 curl_setopt($handle, CURLOPT_VERBOSE, true);
 curl_setopt($handle, CURLOPT_RETURNTRANSFER, true);
-if (!curl_setopt($handle, CURLOPT_STDERR, fopen("php://memory", "w+")))
+if (!@curl_setopt($handle, CURLOPT_STDERR, fopen("php://memory", "w+")))
     die("skip fopencookie not supported on this platform");
 --FILE--
 <?php