[FIX] website_sale: flag partners as customers

When placing an order in the ecommerce, it's
seems obvious that the partner is a customer.

Nevertheless, It wasn't flagged as such in
its partner from, preventing
to see him in the customers list

Fixes #2422
Closes #2881

addons/website_sale/controllers/main.py

@@ -526,7 +526,7 @@ class website_sale(http.Controller):
 
         partner_lang = request.lang if request.lang in [lang.code for lang in request.website.language_ids] else None
 
-        billing_info = {}
+        billing_info = {'customer': True}
         if partner_lang:
             billing_info['lang'] = partner_lang
         billing_info.update(self.checkout_parse('billing', checkout, True))