[CLIENT] Client confirmation dialogs can get disabled during matchmaking

I deleted a friend, which displays the confirmation dialog. But when the matchmaking process finished before I had a chance to dismiss the dialog, the dialog disappeared automatically and I could not get it to reappear until exiting the client and starting it up again. This prevents users from deleting friends, and potentially other actions that require a confirmation dialog.

I am able to reproduce this consistently by following the same steps above.