manifest.json 404s if the trailing `/` is removed in published link

[yaustar]

Thread: https://forum.playcanvas.com/t/solved-manifest-json-404s-and-timeouts-on-newly-published-playcanvas-build/26790/

https://playcanv.as/p/xrWromyG/ is fine but using https://playcanv.as/p/xrWromyG would give GET https://playcanv.as/p/xrWromyGmanifest.json 404 as it looks like we may be generating paths based on the URL?