* Remove another header for websocket connections

* Fix small bake issue

* Update crates

Updated crates and adjusted code where needed.
One major update is Rocket rc4, no need anymore (again) for crates.io patching.

The only item still pending is openssl/openssl-sys for which we need to
wait if https://github.com/sfackler/rust-openssl/pull/2094 will be
merged. If, then we can remove the pinned versions for the openssl crate.