Allow port value to be used in port forwarding table more than once

[Asok]

Using AC1750 / WZR-D1800H

 

I cannot add the same port number to the port forwarding table more than once, even if one of them is disabled.  For example, Xbox360 takes 6 entries and I like to add all my Xboxes and then be able to toggle one off and the other on when changing rooms  I would love to create an Xbox1 group with the 6 entries it needs and an Xbox2 group with the same 6 entries to a different IP.  I would only ever have one enabled at a time.  Right now, the UI says "Port number is duplicated", even if the port that is already in the table is disabled.