Re-enable tokio-rustls now that it has a stable release (#429)

examples/akamai.rs

@@ -1,5 +1,3 @@
-fn main() {}
-/* TODO: re-enable when tokio-rustls is updated
 use h2::client;
 use http::{Method, Request};
 use tokio::net::TcpStream;
@@ -75,4 +73,3 @@ pub async fn main() -> Result<(), Box<dyn Error>> {
     }
     Ok(())
 }
-*/