If we have no released version of an app also show an error instead of the app install dialog

dashboard/src/views/AppstoreView.vue

@@ -243,8 +243,8 @@ async function onHashChange() {
     const version = params.get('version') || 'latest';
 
     const [error, result] = await appstoreModel.get(appId, version);
-    if (error) {
-      console.error(error);
+    if (error || !result.manifest) {
+      if (error) console.error(error);
       return inputDialog.value.info({
         title: t('appstore.appNotFoundDialog.title'),
         message: t('appstore.appNotFoundDialog.description', { appId, version }),