loot tracker: fix cox loot being double-counted after region load

It is possible to hit region loads in cox after checking the chest once, so additionally check we are no longer in an instance.

runelite-client/src/main/java/net/runelite/client/plugins/loottracker/LootTrackerPlugin.java

@@ -370,7 +370,7 @@ public class LootTrackerPlugin extends Plugin
 	@Subscribe
 	public void onGameStateChanged(final GameStateChanged event)
 	{
-		if (event.getGameState() == GameState.LOADING)
+		if (event.getGameState() == GameState.LOADING && !client.isInInstancedRegion())
 		{
 			chestLooted = false;
 		}