fix for python 23

Wrapping/Python/vtkPythonAppInit.cxx

@@ -91,7 +91,7 @@ static vtkMPICleanup VTKMPICleanup;
 #endif // VTK_COMPILED_USING_MPI
 
 extern "C" {
-  extern DL_EXPORT(int) Py_Main(int, char **);
+  extern DL_IMPORT(int) Py_Main(int, char **);
 }
 
 static void vtkPythonAppInitEnableMSVCDebugHook();