before this commit, it was raising an error while try to preview the certificate after this commit, prevent the preview of certificate, as it is not possible to set the preview of certificate task- 2623276 closes odoo/odoo#78911 X-original-commit: 8c51d83855566cb21578f18ebf460cead484aed2 Signed-off-by: Warnon Aurélien (awa) <awa@odoo.com>