TUN-2785: Use reconnect token by default

cmd/cloudflared/tunnel/cmd.go

@@ -980,6 +980,7 @@ func tunnelFlags(shouldHide bool) []cli.Flag {
 		altsrc.NewBoolFlag(&cli.BoolFlag{
 			Name:    "use-reconnect-token",
 			Usage:   "Test reestablishing connections with the new 'reconnect token' flow.",
+			Value:   true,
 			EnvVars: []string{"TUNNEL_USE_RECONNECT_TOKEN"},
 			Hidden:  true,
 		}),