HTTP auth fails when the `Authorization` header is presented lowercase

[Fusl]

As title says. If the HTTP basic auth header is presented as

authorization: Basic <base64>

instead of

Authorization: Basic <base64>

the authorization fails with a 401 {"error":{"message":"Authentication required"}}.

[hyperblast]

Thanks for nothing this.

HTTP headers should be case insensitive, but this is not implemented yet.