Description:
------------
If $_SERVER['QUERY_STRING'] is set in php before making the call to create a new HttpQueryString object and that object is set with the global parameter to true, it does not get the value of that variable.

Reproduce code:
---------------
$_SERVER['QUERY_STRING'] = 'foo=bar';
$query = new HttpQueryString(true, array('foo2' => 'bar2'));
var_dump($query);

Expected result:
----------------
object(HttpQueryString)#1 (2) {
  ["queryArray:private"]=>
  &array(2) {
    ["foo"]=>
    string(4) "bar"
    ["foo2"]=>
    string(4) "bar2"
  }
  ["queryString:private"]=>
  &string(9) "foo=bar&foo2=bar2"
}

Actual result:
--------------
object(HttpQueryString)#1 (2) {
  ["queryArray:private"]=>
  &array(1) {
    ["foo2"]=>
    string(4) "bar2"
  }
  ["queryString:private"]=>
  &string(9) "foo2=bar2"
}