use 80/443 as ws/wss default port (#1700)

easytier/src/common/dns.rs

@@ -74,6 +74,7 @@ pub async fn socket_addrs(
         .or_else(default_port_number)
         .ok_or(Error::InvalidUrl(url.to_string()))?;
     // See https://github.com/EasyTier/EasyTier/pull/947
+    // here is for compatibility with old version
     let port = match port {
         0 => match url.scheme() {
             "ws" => 80,