Fix Display impl, resolving clippy

src/server.rs

@@ -16,12 +16,7 @@ use hyper::{Body, Method, Request, Response, Server as HyperServer};
 use libflate::gzip;
 use route_recognizer::{Params, Router};
 use std::{
-	cmp::Ordering,
-	io,
-	pin::Pin,
-	result::Result,
-	str::{from_utf8, Split},
-	string::ToString,
+	cmp::Ordering, fmt::Display, io, pin::Pin, result::Result, str::{from_utf8, Split}, string::ToString
 };
 use time::Duration;
 
@@ -67,12 +62,12 @@ impl CompressionType {
 	}
 }
 
-impl ToString for CompressionType {
-	fn to_string(&self) -> String {
+impl Display for CompressionType {
+	fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
 		match self {
-			Self::Gzip => "gzip".to_string(),
-			Self::Brotli => "br".to_string(),
-			Self::Passthrough => String::new(),
+			Self::Gzip => write!(f, "gzip"),
+			Self::Brotli => write!(f, "br"),
+			Self::Passthrough => Ok(()),
 		}
 	}
 }