luci-mod-admin-full: fix revert page

This fix the strange redirect link, a bug with uwsgi where the controller
is empty and a bug with the revert page showing the apply content empty.

Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
[drop unrelated revert.html template change]
Signed-off-by: Jo-Philipp Wich <jo@mein.io>