[UPDATE] minor update

[UPDATE] minor update in order to avoid limitation on parameters type
passed to operation when the value must be an Enumeration value (test
case : http://graphical.weather.gov/xml/DWMLgen/wsdl/ndfdXML.wsdl,
NDFDgen($_latitude,$_longitude,$_product,$_startTime,$_endTime,$_unit,MyndfdStructWeatherParametersType
$_myndfdStructWeatherParametersType) instead of
NDFDgen($_latitude,$_longitude,MyndfdEnumProductType
$_myndfdEnumProductType,$_startTime,$_endTime,MyndfdEnumUnitType
$_myndfdEnumUnitType,MyndfdStructWeatherParametersType
$_myndfdStructWeatherParametersType))