v1.21.2: Minfilia Warde - Echo 2

-- Fixes a problem with nonstandard URLs and redirects --

This could allow an attacker to craft an Anubis pass-challenge URL
that forces a redirect to nonstandard URLs, such as the `javascript:`
scheme which executes arbitrary JavaScript code in a browser context
when the user clicks the "Try again" button.

This has been fixed by disallowing any URLs without the scheme `http`
or `https`.