Added support fo the "npc" meta data tag assigned by Citizens to the …

…AFK Component's NPC compatibility system

src/main/java/com/sk89q/commandbook/AFKComponent.java

@@ -216,7 +216,7 @@ public void run() {
             final Player target = session.getPlayer();
             if (target == null || !session.getPlayer().isValid()) continue;
 
-            if (onlinePlayers != null && !onlinePlayers.contains(target)) {
+            if (onlinePlayers != null && (target.hasMetadata("npc") || !onlinePlayers.contains(target))) {
                 continue;
             }