Revert "Don't append a trailing slash to Wagtail URLs"
Revert "Don't append a trailing slash to Wagtail URLs"

This reverts commit 143169af166a1380c8e7ec532aca4f1ebb16aa49.

DNSUsher/securethenews,freedomofpress/securethenews,freedomofpress/securethenews,DNSUsher/securethenews,freedomofpress/securethenews,freedomofpress/securethenews,DNSUsher/securethenews