[FIX] account_edi_ubl_cii: mistaken duplicated line of code

A line of code has been duplicated while fixing a failed forward port,
remove it.
(see: https://github.com/odoo/odoo/commit/7f93f72a4f874e7073c0fec8ab0a89ebbd13e029

)

closes odoo/odoo#126390

Signed-off-by: William André (wan) <wan@odoo.com>