website_multi/views/res_config.xml

<?xml version="1.0" encoding="utf-8"?>
<openerp>
    <data>

        <record id="view_website_config_setting_website_multi" model="ir.ui.view">
            <field name="name">Website Multi Settings</field>
            <field name="model">website.config.settings</field>
            <field name="inherit_id" ref="website.view_website_config_settings" />
            <field name="arch" type="xml">
                <xpath expr="//field[@name='website_id']" position="attributes">
                    <attribute name="invisible">0</attribute>
                </xpath>
            </field>
        </record>

    </data>
</openerp>