Description:
------------
When encoding is set for both SoapClient and SoapServer (i.e. ISO-8859-1) parameters are encoded automatically. But this doesn't apply to SoapFault. Including any national character in fault string causes an error "Fatal error: Uncaught SoapFault exception: [Client] looks like we got no XML document in ..."

Reproduce code:
---------------
[client]
<?php
$client = new SoapClient('a.wsdl'
		,array('encoding'	=> 'ISO-8859-1')
	);
$res = $client->Test();
?>

[server]
<?php
function Test() {
return new SoapFault('Test', 'This is our fault: ?');
}
$server = new SoapServer('a.wsdl', array('encoding' => 'ISO-8859-1'));
$server->addFunction('Test');
$server->handle();
?>

[a.wsdl]
//not important for this error


Expected result:
----------------
Soap exception with message being SoapFault's parameter

Actual result:
--------------
Fatal error: Uncaught SoapFault exception: [Client] looks like we got no XML document in ...