Before this commit, a participating badge was displayed on the event even if the user's registration has been canceled. This is a strange behavior. After this commit, the participating badge will be hidden if all the user's registration have been canceled. Task ID-2432546 closes odoo/odoo#65702 X-original-commit: 125e5401123d8e4bc7656ac7534cc9290451adbc Signed-off-by: Thibault Delavallee (tde) <tde@openerp.com>