Force match sticks around forever if target goes offline

[Beyley]

If you try to force match to a user, then that user goes offline, dive-in will cease to work forever until that player comes online and you force match, or you clear the force match, this is a very bad user experience, we should clear the force match unconditionally after a user tries to dive in.

We should send a notification to the user saying something along the lines of "User (X) was not online at the time you tried to force match, we've cleared the force match for you, please try again.", or at least something to get the same information across.