chore(portforward): move vpn gateway obtention within port forwarding service

internal/vpn/portforward.go

@@ -1,22 +1,13 @@
 package vpn
 
 import (
-	"fmt"
-
 	"github.com/qdm12/gluetun/internal/configuration/settings"
 	"github.com/qdm12/gluetun/internal/portforward/service"
 )
 
 func (l *Loop) startPortForwarding(data tunnelUpData) (err error) {
-	gateway, err := l.routing.VPNLocalGatewayIP(data.vpnIntf)
-	if err != nil {
-		return fmt.Errorf("obtaining VPN local gateway IP for interface %s: %w", data.vpnIntf, err)
-	}
-	l.logger.Info("VPN gateway IP address: " + gateway.String())
-
 	partialUpdate := service.Settings{
 		PortForwarder: data.portForwarder,
-		Gateway:       gateway,
 		Interface:     data.vpnIntf,
 		ServerName:    data.serverName,
 		VPNProvider:   data.portForwarder.Name(),