refactor the code related to xtcp (#3449)

pkg/config/client_test.go

@@ -661,6 +661,9 @@ func Test_LoadClientBasicConf(t *testing.T) {
 				BindAddr:   "127.0.0.1",
 				BindPort:   9001,
 			},
+			Protocol:         "quic",
+			MaxRetriesAnHour: 8,
+			MinRetryInterval: 90,
 		},
 	}