Rewrite trailing slashes to canonical URL
Rewrite trailing slashes to canonical URL

If user hits https://www.gov.uk/browse/driving/, it redirects to
https://www.gov.uk/browse/driving and does load the correct page.

Currently on mirror, we get a 503 in above scenario, because the
redirection is usually handled by the application.

This commit adds a rewrite which will do that redirection for all URLs
ending in a slash - I've confirmed that we don't have any URLs which
should end in a trailing slash, so this change will make the mirror
match the behaviour of the GOV.UK Stack.

This [Fixes #56337502] once it has been deployed

alphagov/govuk_mirror-puppet,alphagov/govuk_mirror-puppet,alphagov/govuk_mirror-puppet