Exit daily challenge screen when going offline

[bdach]

This sort of thing is bound to happen when rewriting screens from scratch without invoking abstract eldritch entities sometimes. Damned if you do, damned if you don't...

[bdach]

Readers will note that this copy of this logic contains an else branch that claims that it is "[handling] the case where a child screen is current (ie. gameplay)."

Dear reader, it does not, because the invocation of this method is copiously scheduled:

osu/osu.Game/Screens/OnlinePlay/OnlinePlayScreen.cs

Lines 78 to 82 in aded31b

	private void onlineStateChanged(ValueChangedEvent<APIState> state) => Schedule(() =>
	{
	if (state.NewValue != APIState.Online)
	Schedule(forcefullyExit);
	});

which means it will not get called if the screen is not current. So this just doesn't work. This particular oopsie blames back to 5b405ab which means I am not touching it with a ten foot pole here. (Unless you'd like me to remove it?)