Production cost takes into account the cost price of cancelled production inputs

Currently, the cost of a production is adding the product cost price of the cancelled movements.

Example: Production inputs:

product	quantity	cost price	state
product1	1	10	cancelled
product2	1	10	done
product3	1	10	done
product4	1	10	done

This production is returning 40(€) as cost price but it should return 30, isn't it? So I propose to modify get_cost and on_change_with_cost functions to do not sum cancelled moves cost price.