Add uTLS client

common/tls/utls_stub.go

@@ -0,0 +1,13 @@
+//go:build !with_utls
+
+package tls
+
+import (
+	"github.com/sagernet/sing-box/adapter"
+	"github.com/sagernet/sing-box/option"
+	E "github.com/sagernet/sing/common/exceptions"
+)
+
+func newUTLSClient(router adapter.Router, serverAddress string, options option.OutboundTLSOptions) (Config, error) {
+	return nil, E.New(`uTLS is not included in this build, rebuild with -tags with_utls`)
+}