Removing stray </div> from o2_helloworld project in staging

`o2-helloworld-fix` should have been rebased to the latest common parent of `staging` and `development`, but unfortunately it wasn't. Rather than backing it out of `development` to redo it all, `o2-helloworld-staging-fix` has been rebased, which means when we finally reconcile staging and development, we'll end up with two similar commits with different SHAs. Annoying, but not the end of the world.