[FIX] stock_account: default new price if compute from BoM

When the new standard price is computed from the BoM (thanks to module
`product_extended`), the price suggested is still the standard price of
the product.

addons/stock_account/wizard/stock_change_standard_price.py

@@ -36,7 +36,7 @@ class change_standard_price(osv.osv_memory):
 
         res = super(change_standard_price, self).default_get(cr, uid, fields, context=context)
 
-        price = product_obj.standard_price
+        price = context.get('default_new_price') or product_obj.standard_price
 
         if 'new_price' in fields:
             res.update({'new_price': price})