[FIX] tools : Save translation for record with no model data record

According to standard flow when a record is created by user we do not make
a model data entry and if he does any changes in standard record we change the
noupdate to true on conditional bases to keep the data same while upgrading
but in the case of user created record where there is no model data entry the
engine should consider it as noupdate true but without the model data entry
select query gets null resulting into engine considering it false and the update
case are designed to consider true or else  so for null case it falls under else
part hence creating issue in product_template name and cowed website menu
So,we have updated the case accordingly.

closes odoo/odoo#129518

Signed-off-by: Raphael Collet <rco@odoo.com>