[FIX] sale_quotation_builder: Update template header message

Update header message to match changes in the following commit:
https://github.com/odoo/odoo/commit/8ba6e3b0c3bf856308b4d58158392d0e99d2b58e



opw-2631125

closes odoo/odoo#76748

Signed-off-by: bon-odoo <nboulif@users.noreply.github.com>