Fix logic error with living entity collision reduction.

The previous version missed the entire point of the change and made it only skip collision on NON living entities... which is not often at all.

It was meant to only Skip Living->Living, or else we won't get any gain...

CraftBukkit-Patches/0020-Reduce-number-of-LivingEntity-collision-checks.patch

@@ -1,4 +1,4 @@
-From 3a77832f283c73ab7a576ada6942ddd35ebe7178 Mon Sep 17 00:00:00 2001
+From e9079818151c8df92e2d927b0f4f3308d9cea113 Mon Sep 17 00:00:00 2001
 From: Aikar <aikar@aikar.co>
 Date: Fri, 18 Jan 2013 19:31:14 -0500
 Subject: [PATCH] Reduce number of LivingEntity collision checks.
@@ -8,7 +8,7 @@ Subject: [PATCH] Reduce number of LivingEntity collision checks.
  1 file changed, 8 insertions(+)
 
 diff --git a/src/main/java/net/minecraft/server/EntityLiving.java b/src/main/java/net/minecraft/server/EntityLiving.java
-index b2481aa..d33cfb4 100644
+index b2481aa..bbbb008 100644
 --- a/src/main/java/net/minecraft/server/EntityLiving.java
 +++ b/src/main/java/net/minecraft/server/EntityLiving.java
 @@ -1402,12 +1402,20 @@ public abstract class EntityLiving extends Entity {
@@ -28,10 +28,10 @@ index b2481aa..d33cfb4 100644
              for (int i = 0; i < list.size(); ++i) {
                  Entity entity = (Entity) list.get(i);
  
-+                if (!(entity instanceof EntityLiving) && skip) { continue; } // Spigot
++                if (entity instanceof EntityLiving && skip) { continue; } // Spigot
                  if (entity.M()) {
                      this.o(entity);
                  }
 -- 
-1.8.1-rc2
+1.8.1.1