[MERGE][FIX] base_vat_autocomplete: add missing attrs

VAT number should be readonly when parent_id is set
This is already what is done in base.view_partner_form and
base.view_partner_short_form

closes odoo/odoo#28190

addons/base_vat_autocomplete/views/res_partner_views.xml

@@ -8,7 +8,7 @@
             <xpath expr="//field[@name='vat']" position="replace">
             </xpath>
             <xpath expr="//label[@for='street']" position="before">
-                <field name="vat" string="VAT" placeholder="e.g. BE0477472701"/>
+                <field name="vat" string="VAT" placeholder="e.g. BE0477472701" attrs="{'readonly': [('parent_id','!=',False)]}"/>
             </xpath>
         </field>
     </record>
@@ -21,7 +21,7 @@
             <xpath expr="//field[@name='vat']" position="replace">
             </xpath>
             <xpath expr="//label[@for='street']" position="before">
-                <field name="vat" string="VAT" placeholder="e.g. BE0477472701"/>
+                <field name="vat" string="VAT" placeholder="e.g. BE0477472701" attrs="{'readonly': [('parent_id','!=',False)]}"/>
             </xpath>
         </field>
     </record>

doc/cla/corporate/brahoo.md

@@ -0,0 +1,15 @@
+The Netherlands, 2018-10-24
+
+Brahoo B.V. agrees to the terms of the Odoo Corporate Contributor License
+Agreement v1.0.
+
+I declare that I am authorized and able to make this agreement and sign this
+declaration.
+
+Signed,
+
+Cas Vissers c.vissers@brahoo.nl https://github.com/CasVissers
+
+List of contributors:
+
+Cas Vissers c.vissers@brahoo.nl https://github.com/CasVissers