feat: only update hostname if set

pkg/system/init.go

@@ -12,9 +12,12 @@ import (
 func Configure(appConfig *config.Config) error {
 	log.Print("[INFO] Configure system")
 	// configure hostname
+	if appConfig.Hostname != "" {
+		log.Printf("[INFO] update hostname to %s", appConfig.Hostname)
 		if err := network.SetHostname(appConfig.Hostname); err != nil {
 			log.Printf("[ERROR] setting hostname failed: %s", err)
 		}
+	}
 	// configure network connections
 	for _, connection := range appConfig.Network.Connections {
 		err := util.WithConnection(func(conn *dbus.Conn) error {