Fix link library for vtk version <= 5.6

Author: patmarion

CMakeLists.txt

@@ -48,7 +48,7 @@ if(PythonQt_USE_VTK)
   if(${VTK_VERSION_MAJOR}.${VTK_VERSION_MINOR} VERSION_GREATER 5.6)
     set(VTK_LIBRARIES vtkPythonCore)
   else()
-    set(VTK_LIBRARIES vtkCommon)
+    set(VTK_LIBRARIES vtkCommonPythonD)
   endif()
 else()
   remove_definitions(-DPYTHONQT_USE_VTK)