fix ipv4 parsing in Forwarded

src/main.rs

@@ -37,7 +37,7 @@ async fn root(header: HeaderMap, ConnectInfo(socket_info): ConnectInfo<SocketAdd
                     return res;
                 }
             } else {
-                let res: String = chars.take_while(|c| *c != 'c').collect();
+                let res: String = chars.take_while(|c| *c != ',').collect();
                 if res.parse::<Ipv4Addr>().is_ok() {
                     return res;
                 }