Use captured args in format string (#558)

https-tls/openssl/src/main.rs

@@ -5,7 +5,7 @@ use openssl::ssl::{SslAcceptor, SslFiletype, SslMethod};
 
 /// simple handle
 async fn index(req: HttpRequest) -> Result<HttpResponse, Error> {
-    println!("{:?}", req);
+    println!("{req:?}");
     Ok(HttpResponse::Ok()
         .content_type("text/plain")
         .body("Welcome!"))