FEATURE: Support backup uploads/downloads directly to/from S3.

This reverts commit 3c59106bac4d79f39981bda3ff9db7786c1a78a0.

app/assets/javascripts/admin/controllers/admin-backups-index.js.es6

@@ -1,9 +1,15 @@
 import { ajax } from "discourse/lib/ajax";
+import computed from "ember-addons/ember-computed-decorators";
 
 export default Ember.Controller.extend({
   adminBackups: Ember.inject.controller(),
   status: Ember.computed.alias("adminBackups.model"),
 
+  @computed
+  localBackupStorage() {
+    return this.siteSettings.backup_location === "local";
+  },
+
   uploadLabel: function() {
     return I18n.t("admin.backups.upload.label");
   }.property(),