Fix app backup before updates

we were passing the current manifest to the backup code which meant that
the app version and manifest was incorrect.

src/apptask.js

@@ -439,7 +439,7 @@ function backup(app, callback) {
 
     async.series([
         updateApp.bind(null, app, { installationProgress: '10, Backing up' }),
-        backups.backupApp.bind(null, app, app.manifest.addons),
+        backups.backupApp.bind(null, app, app.manifest),
 
         // done!
         function (callback) {
@@ -638,7 +638,7 @@ function update(app, callback) {
 
             async.series([
                 updateApp.bind(null, app, { installationProgress: '30, Backup app' }),
-                backups.backupApp.bind(null, app, app.oldConfig.manifest.addons)
+                backups.backupApp.bind(null, app, app.oldConfig.manifest)
             ], next);
         },