[FIX] website_customer: error if customer without countries

For customer without countries, we get False instead of tuple:
 (country_id, 'country name')

Introduced by a35cce2008.

opw-703234

addons/website_customer/controllers/main.py

@@ -51,7 +51,7 @@ class WebsiteCustomer(http.Controller):
         if country_id:
             domain += [('country_id', '=', country_id)]
             curr_country = Country.browse(country_id)
-            if country_id not in map(lambda x: x['country_id'][0], countries):
+            if country_id not in (x['country_id'][0] for x in countries if x['country_id']):
                 if curr_country.exists():
                     countries.append({
                         'country_id_count': 0,