can't refer to java.lang.Exception in gererated fault code

if wsdl and wsdl types are using same name namespace, also in the types we define a fault with name
<element name="exception">
then generated code like
public class ServiceException extends Exception {
The exception here should be java.lang.Exception,
but the java compile consider it as inner faulttype org.apache.hello_world_soap_http_provider.Exception in the
same package, which cause compilation error.

We should always use java.lang.Exception in the generated code to avoid such error