How to get rid of the "You have exited the battle for wintergrasp." message?

I queued to wintergrasp. I left for toilet. Queue popped while I was afk and now I can't get rid of this message.

Edit: Tried flying in with flightmaster, now I'm stuck on the flightmaster gryphon flying on the ground with runnin speed, phased out of the battle. Can't take falldmg, can't drown myself either, heh,,,

Edit 2: The battle for wg ended and relogging worked, now im flying through buildings back to dalaran and from the to wintersgrasp. Someone said that flying in wintersgrasp with your mount (not via flightmaster like I did) would fix the error, but I can't really test it now.

You can fly to Wintergrasp and join it that way. The message will disappear when you join Wintergrasp.