Controller fails if envelope message provides header arguments

The generated WSDL does not provide header attributes.
If some services decides to send header arguments anyway, services_controller_execute() will parse these arguments and fail.

Result is that the body arguments don't get parsed.

Works:

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:urn="urn:xmethods-delayed-quotes">
   <soapenv:Header>
   </soapenv:Header>
   <soapenv:Body>
      <urn:MYFUNCTION_CRUD>
         <MyProperty>TEST</MyProperty>
      </urn:MYFUNCTION_CRUD>
   </soapenv:Body>
</soapenv:Envelope>

Breaks:

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:urn="urn:xmethods-delayed-quotes">
   <soapenv:Header>
      <MyCoolHeaderProperty>sender</MyCoolHeaderProperty>
   </soapenv:Header>
   <soapenv:Body>
      <urn:MYFUNCTION_CRUD>
         <MyProperty>TEST</MyProperty>
      </urn:MYFUNCTION_CRUD>
   </soapenv:Body>
</soapenv:Envelope>