A linha deve ser removida
/adminXXXX/themes/default/template/controllers/products/helpers/form/form.tpl: https://github.com/PrestaShop/PrestaShop/blob/5566c2d9d7e4ab88a201b2c5cf10e1cda2ff7150/admin-dev/themes/default/template/controllers/products/helpers/form/form.tpl#L252-L254
Se necessitarem de ajuda é só dizer.
SKYPE : luisleitaoaudio 