lib/model: Use up to date device name, do not provide name to unknown devices (fixes #4164)

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4168

cmd/syncthing/main.go

@@ -795,7 +795,7 @@ func syncthingMain(runtimeOptions RuntimeOptions) {
 		ldb.ConvertSymlinkTypes()
 	}
 
-	m := model.NewModel(cfg, myID, myDeviceName(cfg), "syncthing", Version, ldb, protectedFiles)
+	m := model.NewModel(cfg, myID, "syncthing", Version, ldb, protectedFiles)
 
 	if t := os.Getenv("STDEADLOCKTIMEOUT"); len(t) > 0 {
 		it, err := strconv.Atoi(t)
@@ -964,15 +964,6 @@ func syncthingMain(runtimeOptions RuntimeOptions) {
 	os.Exit(code)
 }
 
-func myDeviceName(cfg *config.Wrapper) string {
-	devices := cfg.Devices()
-	myName := devices[myID].Name
-	if myName == "" {
-		myName, _ = os.Hostname()
-	}
-	return myName
-}
-
 func setupSignalHandling() {
 	// Exit cleanly with "restarting" code on SIGHUP.