[FIX] website_mail: prevent crash
[FIX] website_mail: prevent crash

`self` is a controller, not a model, thus we use the request to get the
environment.

opw-2160614

closes odoo/odoo#42350

X-original-commit: ac456d8d12bfc26addb3f097aa5552176f6fb765
Signed-off-by: Richard Mathot (rim) <5f1d1f6ddf3e29edc21cd1c407a621f18d6c734e@openerp.com>

ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo