[IMP] account : set move_line "Disc%" field on optional hide

Remove groups="base.group_no_one" & set optional to "hide" on
"Disc%" to allow displaying discount field when needed.

closes odoo/odoo#47558

Task: 2214301
Signed-off-by: oco-odoo <oco-odoo@users.noreply.github.com>

addons/account/views/account_move_views.xml

@@ -704,7 +704,7 @@
                                         <field name="product_uom_category_id" invisible="1"/>
                                         <field name="product_uom_id" string="UoM" groups="uom.group_uom" optional="show"/>
                                         <field name="price_unit" string="Price"/>
-                                        <field name="discount" string="Disc.%" groups="base.group_no_one" optional="show"/>
+                                        <field name="discount" string="Disc.%" optional="hide"/>
                                         <field name="tax_ids" widget="many2many_tags"
                                                domain="[('type_tax_use', '=?', parent.invoice_filter_type_domain), ('company_id', '=', parent.company_id)]"
                                                context="{'append_type_to_tax_name': not parent.invoice_filter_type_domain}"