Remove duplicate padStart polyfill in client helpers
A String.padStart
polyfill is in the client's helpers twice. The only difference is that one has comments and one doesn't.
I would do a PR for this but I'm not easily able to right now, but this is a very quick fix.
https://gitlab.com/Isleward/isleward/blob/master/src/client/js/misc/helpers.js#L63