trying to fix panic

src/main.rs

@@ -5,6 +5,7 @@ extern crate tokio;
 mod configuration;
 
 use crate::configuration::Settings;
+use std::net::SocketAddr;
 use tokio::io;
 use tokio::net::TcpListener;
 use tokio::prelude::*;
@@ -21,7 +22,7 @@ fn main() {
     println!("Listening on port {}", settings.port);
 
     let addr = format!("{}:{}", settings.listen, settings.port)
-        .parse()
+        .parse::<SocketAddr>()
         .unwrap();
 
     let listener = TcpListener::bind(&addr).unwrap();