You can clone with
HTTPS or Subversion.
In the same sense, that the option
http://piwik.org/faq/how-to/#faq_91 force_ssl does not enforce https for piwik.php and piwik.js it should also not enforce that https for the optOut iframe:
index.php?module=CoreAdminHome&action=optOut (sometimes with additional language=de or similar parameter)
Thanks for the report
(In ) Fixes #3145