Description:
------------
The vartype of the 123 key changed after serialization, it should be consistent.


Reproduce code:
---------------
<?php
    
    $data = array(
        '123' => 'zahl',
        'Foo' => 'bar',
    );
    
    var_dump( $data );
    var_dump( wddx_deserialize( wddx_serialize_value( $data ) ) );
    
    highlight_file( __FILE__ );
?>



Expected result:
----------------
array(2) {
  ["123"]=>
  string(4) "zahl"
  ["Foo"]=>
  string(3) "bar"
}
array(2) {
  ["123"]=>
  string(4) "zahl"
  ["Foo"]=>
  string(3) "bar"
}


Actual result:
--------------
array(2) {
  [123]=>
  string(4) "zahl"
  ["Foo"]=>
  string(3) "bar"
}
array(2) {
  ["123"]=>
  string(4) "zahl"
  ["Foo"]=>
  string(3) "bar"
}