[FIX] product: when duplicating a product, keep the language in the context

At the time of the context_wo_lang patch (7.0 revision 6577), the orm did not keep the language in copy_data, this patch intended to be more consistent.
Since server revision 5146 7.0, the new behaviour is to use the translated version in copy_data. Removign this change will be more consistent with the orm.

The expected behaviour is now the following:
In user lang: translated product name + translated '(copy)'
In other lang: same as original product

bzr revid: mat@openerp.com-20140508153236-00gxvxenh8fy03km

addons/product/product.py

@@ -728,11 +728,7 @@ class product_product(osv.osv):
         if not default:
             default = {}
 
-        # Craft our own `<name> (copy)` in en_US (self.copy_translation()
-        # will do the other languages).
-        context_wo_lang = context.copy()
-        context_wo_lang.pop('lang', None)
-        product = self.read(cr, uid, id, ['name'], context=context_wo_lang)
+        product = self.read(cr, uid, id, ['name'], context=context)
         default = default.copy()
         default.update(name=_("%s (copy)") % (product['name']))