Add: url-test proxy group support

adapters/direct.go

@@ -30,6 +30,10 @@ func (d *DirectAdapter) Conn() net.Conn {
 type Direct struct {
 }
 
+func (d *Direct) Name() string {
+	return "Direct"
+}
+
 func (d *Direct) Generator(addr *C.Addr) (adapter C.ProxyAdapter, err error) {
 	c, err := net.Dial("tcp", net.JoinHostPort(addr.String(), addr.Port))
 	if err != nil {