Xray-core: Reduce error log usage for performance (#6796)

https://github.com/XTLS/Xray-core/pull/6796#issuecomment-5807809588

proxy/vmess/encoding/client.go

@@ -209,7 +209,7 @@ func (c *ClientSession) DecodeResponseHeader(reader io.Reader) (*protocol.Respon
 	defer buffer.Release()
 
 	if _, err := buffer.ReadFullFrom(c.responseReader, 4); err != nil {
-		return nil, errors.New("failed to read response header").Base(err).AtWarning()
+		return nil, errors.New("failed to read response header").Base(err)
 	}
 
 	if buffer.Byte(0) != c.responseHeader {