Description:
------------
mysqli->insert_id will return zero after mysqli->get_warnings()
(In PHP 5.3.3, it is ok)

Test script:
---------------
$link = new mysqli('localhost', '', '', 'test');

$link->query("DROP TABLE `abcde`");
$link->query("CREATE TABLE abcde (`id` int(11) NOT NULL AUTO_INCREMENT, `value` VARCHAR(255) NOT NULL, PRIMARY KEY (`id`));");
$link->query("INSERT INTO abcde SET `id` = 0");

print_r($link->get_warnings());
echo $link->insert_id . "\n";
echo $link->query("SELECT LAST_INSERT_ID() AS `id`")->fetch_object()->id . "\n";

Expected result:
----------------
mysqli_warning Object
(
    [message] => Field 'value' doesn't have a default value
    [sqlstate] => HY000
    [errno] => 1364
)
1
1

Actual result:
--------------
mysqli_warning Object
(
    [message] => Field 'value' doesn't have a default value
    [sqlstate] => HY000
    [errno] => 1364
)
0
1