Do not use negative product id when there are none for quantities by warehouse

Otherwise this creates rows with negative id which are not valid for stored record.

issue11289
review390181002
(grafted from d084cfdc49ff0ec37c3e99bc57e6d706586defb1)

--HG--
branch : 6.0

product.py

@@ -554,9 +554,9 @@ class ProductQuantitiesByWarehouse(ModelSQL, ModelView):
             product_column = Concat('product.template,', product.template)
             products = [('product.template', i) for i in product_template]
         else:
-            product = context.get('product', -1)
+            product = context.get('product')
             if product is None:
-                product = -1
+                product = []
             if isinstance(product, int):
                 product = [product]
             product_clause = move.product.in_(product or [-1])