Fix for Promotion::Rules::Product

Using Promotion::Rules::Product rules with line item actions (Promotion::Actions::CreateItemAdjustments) was broken when the match_policy was "none".

Conflicts:
	core/spec/models/spree/promotion/rules/product_spec.rb

cherry-picked from 31c76556143263c254ff813f67535d3b268b92b4 in spree master

Closes #142