[FIX] website: restore video loading on page load

Commit [1] broke the building of iframes in existing databases.

[1]: https://github.com/odoo/odoo/commit/b9b29bac14242eb88fc83a1fe5ba2472b64c24ea



opw-2832238

closes odoo/odoo#89726

X-original-commit: fd2aade9
Signed-off-by: Quentin Smetz (qsm) <qsm@odoo.com>