Use entity.dead instead of entity.die()

Fixes #3096

Spigot-Server-Patches/Add-some-Debug-to-Chunk-Entity-slices.patch

@@ -9,7 +9,7 @@ This should hopefully avoid duplicate entities ever being created
 if the entity was to end up in 2 different chunk slices
 
 diff --git a/src/main/java/net/minecraft/server/Chunk.java b/src/main/java/net/minecraft/server/Chunk.java
-index 68cde33565..1d47e47370 100644
+index 68cde33565..3267e87259 100644
 --- a/src/main/java/net/minecraft/server/Chunk.java
 +++ b/src/main/java/net/minecraft/server/Chunk.java
 @@ -0,0 +0,0 @@ public class Chunk implements IChunkAccess {
@@ -52,6 +52,7 @@ index 68cde33565..1d47e47370 100644
          if (entity.currentChunk != null && entity.currentChunk.get() == this) entity.setCurrentChunk(null);
 +        if (entitySlices[i] == entity.entitySlice) {
 +            entity.entitySlice = null;
++            entity.inChunk = false;
 +        }
          if (!this.entitySlices[i].remove(entity)) {
              return;