Fixed HAProxy's PROXY protocol v1 Human-readable header format in Dia…

…lProxy

original code sent the header in the format: PROXY <family> <srcIP>
<srcPort> <dstIP> <dstPort>
according to docs header format should be:
PROXY <family> <srcIP> <dstIP> <srcPort> <dstPort>

this is according
to:
https://www.haproxy.org/download/1.8/doc/proxy-protocol.txt
section
2.1. Human-readable header format (Version 1).

tcpproxy.go

@@ -411,7 +411,7 @@ func (dp *DialProxy) sendProxyHeader(w io.Writer, src net.Conn) error {
 		if srcAddr.IP.To4() == nil {
 			family = "TCP6"
 		}
-		_, err := fmt.Fprintf(w, "PROXY %s %s %d %s %d\r\n", family, srcAddr.IP, srcAddr.Port, dstAddr.IP, dstAddr.Port)
+		_, err := fmt.Fprintf(w, "PROXY %s %s %s %d %d\r\n", family, srcAddr.IP, dstAddr.IP, srcAddr.Port, dstAddr.Port)
 		return err
 	default:
 		return fmt.Errorf("PROXY protocol version %d not supported", dp.ProxyProtocolVersion)