Variables not properly set for backup status? "%s days of backups left"

[kees-closed]

I have this setup in my user system.yaml:

languages:
  supported:
    - nl
    - en
  default_lang: nl
  include_default_lang: true
  include_default_lang_file_extension: true
  translations: true
  translations_fallback: true
  session_store_active: true
  http_accept_language: true
  override_locale: false
  pages_fallback_only: false
  debug: false

And I see this "%s days of backups left" in my backups tab of the admin panel: