fixed updates benchmark: modify mapped property 'randomNumber', otherwise

the changes are never persisted in db (ie. no update statements are executed, because
the model isn't marked as dirty).

ringojs-convenient/app/views.js

@@ -61,7 +61,7 @@ app.get('/updates/:queries?', function(request, queries) {
    for (var i = 0; i < queries; i++) {
       randId = ((Math.random() * 10000) | 0) + 1;
       world = models.store.query('select World.* from World where World.id = :id', {id: randId})[0];
-      world.randomId = ((Math.random() * 10000) | 0) + 1;
+      world.randomNumber = ((Math.random() * 10000) | 0) + 1;
       world.save();
       worlds.push(world.toJSON());
    }