fix builds for iOS because of IPv6 breakage

client/internal/routemanager/systemops_ios.go

@@ -19,7 +19,7 @@ func cleanupRouting() error {
 	return nil
 }
 
-func enableIPForwarding() error {
+func enableIPForwarding(includeV6 bool) error {
 	log.Infof("Enable IP forwarding is not implemented on %s", runtime.GOOS)
 	return nil
 }