Add vtk module path when vtkpython is built as a forwarding executable.

Wrapping/Python/vtkPythonAppInit.cxx

@@ -281,6 +281,7 @@ static void vtkPythonAppInitPrependPath(const char* self_dir)
     // packages in sys.path himself/herself.
     const char* inst_dirs[] = {
       "/lib/python" VTK_PYTHON_VERSION "/site-packages/vtk", // UNIX --prefix
+      "/python" VTK_PYTHON_VERSION "/site-packages/vtk", // UNIX + Forwarding exe --prefix
       "/lib/python/vtk", // UNIX --home
       "/Lib/site-packages/vtk", "/Lib/vtk", // Windows
       "/site-packages/vtk", "/vtk", // Windows