Update upstream for memory leak patch

Spigot-Server-Patches/Fix-Massive-Memory-Leak.patch

@@ -1,26 +0,0 @@
-From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
-From: Aikar <aikar@aikar.co>
-Date: Thu, 31 Mar 2016 19:06:47 -0400
-Subject: [PATCH] Fix Massive Memory Leak
-
-Pathfinder objects are storing references to ChunkCache's, and never cleaning up.
-
-These ChunkCache's then leak other entity objects. Those entity objects then have leaks to their
-own chunk cache. A recursive problem....
-
-Clean up the ChunkCache reference after it is done being used.
-
-diff --git a/src/main/java/net/minecraft/server/PathfinderAbstract.java b/src/main/java/net/minecraft/server/PathfinderAbstract.java
-index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
---- a/src/main/java/net/minecraft/server/PathfinderAbstract.java
-+++ b/src/main/java/net/minecraft/server/PathfinderAbstract.java
-@@ -0,0 +0,0 @@ public abstract class PathfinderAbstract {
-         this.f = MathHelper.d(entityinsentient.width + 1.0F);
-     }
- 
--    public void a() {}
-+    public void a() {this.a = (IBlockAccess) null;} // Paper - Fix massive memory leak. Intentionally casting to ensure compile error if obfuscation changes
- 
-     protected PathPoint a(int i, int j, int k) {
-         int l = PathPoint.b(i, j, k);
---