Handle case where currentTick could be negative

@Aikar is there a better way to handle this?

CraftBukkit-Patches/0024-Enable-Improved-Ping-Sending.patch

@@ -1,4 +1,4 @@
-From 92495f9ed485c619523e3d5e4be1d122b590e6a3 Mon Sep 17 00:00:00 2001
+From dbc277885ec999d8e9ea208555b85b0e4baa34c1 Mon Sep 17 00:00:00 2001
 From: Aikar <aikar@aikar.co>
 Date: Sun, 24 Feb 2013 20:45:20 +1100
 Subject: [PATCH] Enable Improved Ping Sending
@@ -17,7 +17,7 @@ index 8d98a70..4c06a42 100644
  
      public EntityPlayer(MinecraftServer minecraftserver, WorldServer worldserver, GameProfile gameprofile, PlayerInteractManager playerinteractmanager) {
 diff --git a/src/main/java/net/minecraft/server/PlayerList.java b/src/main/java/net/minecraft/server/PlayerList.java
-index 5b0590e..8b3d757 100644
+index 5b0590e..273439a 100644
 --- a/src/main/java/net/minecraft/server/PlayerList.java
 +++ b/src/main/java/net/minecraft/server/PlayerList.java
 @@ -779,6 +779,25 @@ public abstract class PlayerList {
@@ -27,7 +27,7 @@ index 5b0590e..8b3d757 100644
 +        // Spigot start
 +        if ( !players.isEmpty() )
 +        {
-+            int index = MinecraftServer.currentTick % this.players.size();
++            int index = Math.abs( MinecraftServer.currentTick ) % this.players.size();
 +            EntityPlayer player = (EntityPlayer) this.players.get( index );
 +            if ( player.lastPing == -1 || Math.abs( player.ping - player.lastPing ) > 20 )
 +            {
@@ -47,5 +47,5 @@ index 5b0590e..8b3d757 100644
  
      public void sendAll(Packet packet) {
 -- 
-1.8.3.2
+1.8.5.2.msysgit.0