Use shotengai_product

lib/shotengai/snapshot.rb

@@ -103,7 +103,7 @@ module Shotengai
     end
 
     def already_disable
-      shotengai_series.deleted? || product.on_sale?.!
+      shotengai_series.deleted? || shotengai_product.on_sale?.!
     end
 
     def order_was_paid
@@ -195,7 +195,7 @@ module Shotengai
       end
 
       def set_manager
-        self.manager = shotengai_series.product.manager
+        self.manager = shotengai_series.shotengai_product.manager
       end
   end