Remove async-await feature

Author: skade

src/bin/client.rs

@@ -1,5 +1,3 @@
-#![feature(async_await)]
-
 use std::net::ToSocketAddrs;
 
 use futures::select;

src/bin/server.rs

@@ -1,5 +1,3 @@
-#![feature(async_await)]
-
 use std::{
     net::ToSocketAddrs,
     sync::Arc,