Remove unused variable
Remove unused variable

This variable isn’t used by our Jinja templates. Presumably it was
from the time before instances of `Template` were responsible for
showing who the email/text message was being sent to.

alphagov/notifications-admin,gov-cjwaszczuk/notifications-admin,gov-cjwaszczuk/notifications-admin,alphagov/notifications-admin,alphagov/notifications-admin,alphagov/notifications-admin,gov-cjwaszczuk/notifications-admin,gov-cjwaszczuk/notifications-admin