Translation strings with variables aren't being translated

[mouse-reeve]

When there's a translation string that takes a variables, like {{ _("%s users" % instance.users) }} in https://github.com/bookwyrm-social/join-bookwyrm/blob/main/templates/instances/index.html#L51, the string isn't being translated when the site is compiled. The translation string does seem to be loading correctly in the locale file (for example, https://github.com/bookwyrm-social/join-bookwyrm/blob/main/locale/de_DE/LC_MESSAGES/messages.po#L175).

[mouse-reeve]

I've been stumped on this one -- I don't know if you have any leads, @joachimesque