Path normalization does not trim preceding slashes of uri

[Jeroen Hoolmans]

Bug Report

Versions:

tower-http = "0.4.0" (also in master)

Description

For normalization of the path I expected it to trim the slashes on the end and beginning.
Some requests have double preceding slashes which causes for routes to return 404 status code.

#[tokio::main]
async fn main() {
    let app = NormalizePath::trim_trailing_slash(
        Router::new()
            .route("/", get(|| async { "index" }))
            .route("/foo", get(|| async { "foo" }))
    );
    let addr = SocketAddr::from(([127, 0, 0, 1], 3000));
    axum::Server::bind(&addr)
        .serve(app.into_make_service())
        .await
        .expect("Failed to start axum server");
}

To test:

curl http://localhost:3000//foo returns 404