Fix web workers

This reenables web workers - might have to disable that if it affect older android versions.

The problem with web workers was pretty stupid. [This code](https://github.com/SpiderOak/crypton/blob/master/client/src/work.js#L33..L37) was only using the last mention of crypton in the document's script tags. Rather than a multiline fix I just switched the tag order around.

iOS is still slow. Not sure what we can do about that short-term