Bugfix: Migrate from vouch to uffd-nginxauth

[Jonty]

<@russss> freescout is the only thing which uses Vouch to handle auth rather than uffd-nginxauth. And if you get logged out freescout keeps trying to fetch a URL and vouch has an issue where it fills up your cookie storage

This results in a user who has freescout constantly open in a tab eventually getting logged out of everything on the emfcamp domain.