VTK link does not support https

Author: thewtex

docs/index.rst

@@ -13,7 +13,7 @@ compiler environment of your choice.
 
 The suite of CMake tools were created by Kitware in response to the need
 for a powerful, cross-platform build environment for open-source projects
-such as `ITK <https://www.itk.org>`_ and `VTK <https://www.vtk.org>`_.
+such as `ITK <https://www.itk.org>`_ and `VTK <http://www.vtk.org>`_.
 
 The CMake python wheels provide `CMake 3.7.1 <https://cmake.org/cmake/help/v3.7/index.html>`_.