[FIX] mail: translate global variable
[FIX] mail: translate global variable

As the message was set globally in the file, a _lt was needed for a lazy
translation

Fixes odoo/odoo#26288

closes odoo/odoo#31761

Signed-off-by: Martin Trigaux (mat) <cc7c5be316e48d137cbb549833b85d91034d799d@odoo.com>
ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo