Don't hang if socket fails to open

feof($f) returns false if $f is invalid, so if the
socket failed to open we spun forever, causing the tests to
eventually timeout. The test will still fail, but at least
we get meaningful results for the rest.

hphp/test/slow/ext_network/ext_network.php

@@ -52,7 +52,7 @@ fwrite($f,
          "Connection: Close\r\n".
          "\r\n");
 $response = '';
-while (!feof($f)) {
+while ($f && !feof($f)) {
   $line = fgets($f, 128);
   $response .= $line;
 }