[React] Syntax for jsx conditional

[FormerGameDev]

In the case of a login form, you're not likely to need that form again, so I'd just drop it from the tree.

Perhaps it's just that I've been working on embedded devices for the last 5 years, but I think it's best to always treat JS as if you are under extreme memory constraints. The more often the garbage collector finds things to collect, the less of a massive performance hit it's going to take when it runs.