Description of the issue/feature this PR addresses:
Currently, search engines index a SAAS-hosted website twice
(once for the actual domain, and once for the .odoo.com domain)
which is something that should be preventable.
Desired behavior after PR is merged:
If a domain name is configured, and the website is accessed
through a different domain than the configured one, the noindex
tag appears, preventing crawlers from indexing it..
task-2418904
closesodoo/odoo#78425
Signed-off-by: Romain Derie (rde) <rde@odoo.com>