python: Fix vtkWrapPython compiler error ensuring type declaration are first.

This commit will fix the following error:

17>1>..\..\..\VTKv6\Wrapping\Tools\vtkParseHierarchy.c(541) : error C2143: syntax error : missing ';' before 'type'

Change-Id: I67b04a0a864b8220c37281082b973278ca62b8f7