[CLIENT] Expired game invitations could not be dismissed in new client.

A game invitation from a match that had already been completed would not be dismissed no matter how many times I clicked on the displayed button to do so.

http://i.imgur.com/P4G0dxQ.png

Then clicking on the button to accept the invitation produced the following two error messages. The invitation would still not dismiss.

http://i.imgur.com/wjJp9qO.png

Client had to be restarted to remove the message.