Comment 4 for bug 1881201

Lee, we just landed a branch (https://github.com/canonical-web-and-design/maas-ui/commit/265606930777d7794043529ba2f7b852f96a5499) which adds hashes to the js assets, so I've marked this fix committed.

If you're still seeing old cached versions of `index.html` that will have to be investigated on the server (I'm not sure how Twisted web handles cache expiry).