Link to hyper::server::conn is broken

[almielczarek]

The link to the hyper::server::conn module near the top of this page https://docs.rs/hyper/0.12.21/hyper/server/index.html is broken.

The href points to "conn" which returns a 404 on docs.rs.

If it is changed to point to "conn/index.html" it will work.