[FIX] warning: onchange_partner_id

The function _onchange_partner_id must be triggered when the field 'company_id'
is modified like with function _onchange_partner_id in addons/account/models/account_invoice.py
In this way, the account_id is set in 'account.invoice when the 'company_id' is changed.

opw:652918

addons/warning/warning.py

@@ -108,7 +108,7 @@ class purchase_order(osv.Model):
 class account_invoice(osv.osv):
     _inherit = 'account.invoice'
 
-    @api.onchange('partner_id')
+    @api.onchange('partner_id', 'company_id')
     def _onchange_partner_id(self):
         result =  super(account_invoice, self)._onchange_partner_id()
         partner = self.partner_id