URLs in confirmation e-mails should use https

I have received 4 e-mails, including mail address confirmation e-mails with an ephemeral URL in them from 0xacab.org.

all four of these e-mails included URLs back here that start with the http protocol, as in: http://0xacab.org/ (weird, in preview this http:// is getting rewritten as https://, which makes it hard to report this sanely)

These e-mails should use https, not http. (i also think it's a little weird that they have 0xACAB in all caps, but meh)