refactor(control): use default instead of case null in display_status_to_info

hopefully will close#42

control/frontend/src/lib/ts/utils.ts

@@ -100,7 +100,7 @@ export function display_status_to_info(status: DisplayStatus): string {
 			return 'Lädt';
 		case 'host_offline':
 			return 'Offline';
-		case null:
+		default:
 			return '???';
 	}
 }