This change allows Open edX operators to enable password reset
failure email notifications. This is mainly useful for
explicitly informing users that there's no account associated
with their email, so that users can be sure that there wasn't
a problem with the email system.
OSPR-1832
We used to use Django templates and the Sites framework. At some point we
stopped, but this was leftover. The site_name no longer gets set properly.
It's probably a config issue, but not one I want to deal with right before
release, so I'm hardcoding it to link to the prod edx.org site until we
can sort what's what in the morning.
