Signed-off-by: Suguru Hirahara <acioustick@noreply.codeberg.org>

Fixes https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/3108

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/3562

This is a break in backward-compatibility for people disabling
`index.html` creation via the playbook but are managing their static
website files in another way (AUX role, etc).