[FIX] website_sale: deleted category on website product page

Product pages ulrs can be indexed by searches engines.
The product category can be included in the url.
If the category has been deleted, accessing
this page should still work anyway

opw-648008

addons/website_sale/controllers/main.py

@@ -241,6 +241,7 @@ class website_sale(http.Controller):
 
         if category:
             category = category_obj.browse(cr, uid, int(category), context=context)
+            category = category if category.exists() else False
 
         attrib_list = request.httprequest.args.getlist('attrib')
         attrib_values = [map(int,v.split("-")) for v in attrib_list if v]