Update to MC 1.12-pre2

Spigot-Server-Patches/Use-a-Shared-Random-for-Entities.patch

@@ -6,7 +6,7 @@ Subject: [PATCH] Use a Shared Random for Entities
 Reduces memory usage and provides ensures more randomness, Especially since a lot of garbage entity objects get created.
 
 diff --git a/src/main/java/net/minecraft/server/Entity.java b/src/main/java/net/minecraft/server/Entity.java
-index be54c807b..42bd79b10 100644
+index dbaf2863b..aabf25cf2 100644
 --- a/src/main/java/net/minecraft/server/Entity.java
 +++ b/src/main/java/net/minecraft/server/Entity.java
 @@ -0,0 +0,0 @@ public abstract class Entity implements ICommandListener {
@@ -18,9 +18,9 @@ index be54c807b..42bd79b10 100644
          return tag.hasKey("Bukkit.updateLevel") && tag.getInt("Bukkit.updateLevel") >= level;
      }
 @@ -0,0 +0,0 @@ public abstract class Entity implements ICommandListener {
-         this.width = 0.6F;
          this.length = 1.8F;
          this.ax = 1;
+         this.ay = 1.0F;
 -        this.random = new Random();
 +        this.random = SHARED_RANDOM; // Paper
          this.fireTicks = -this.getMaxFireTicks();