[FIX] partner_fax: Add fax field to partner child_ids form

partner_fax/views/res_partner.xml

@@ -31,6 +31,9 @@
             <field name="function" position="after">
                 <field name="fax" placeholder="Fax..." widget="phone"/>
             </field>
+            <xpath expr="//field[@name='child_ids']/form//field[@name='function']" position="after">
+                <field name="fax" placeholder="Fax..." widget="phone"/>
+            </xpath>
         </field>
     </record>