doc: fix dead links to Hunter.

doc/building.dox

@@ -84,8 +84,8 @@ Various examples are provided by the @ref building-examples "Example repository"
 @subsection building-packages-hunter Hunter package
 
 Starting from version 2019.01, stable releases of Magnum are available in the
-[Hunter](https://hunter.sh) CMake-driven package manager. See the
-[magnum package documentation](https://docs.hunter.sh/en/latest/packages/pkg/magnum.html)
+[Hunter](https://hunter.readthedocs.io) CMake-driven package manager. See the
+[magnum package documentation](https://hunter.readthedocs.io/en/latest/packages/pkg/magnum.html)
 for details.
 
 @subsection building-packages-vcpkg Vcpkg package