Fix placement of chunk tracking - Fixes #1199

Spigot had code that returned early in chunk add/remove methods.

This was causing our code added to set current chunks and counts to
be skipped over if the entity was default not persistent but made persistent.

This was the source of many issues

Fixes #1208

Spigot-Server-Patches/Auto-Save-Improvements.patch

@@ -64,7 +64,7 @@ index 1b9eb7f45..ce848d63e 100644
 +    }
  }
 diff --git a/src/main/java/net/minecraft/server/Chunk.java b/src/main/java/net/minecraft/server/Chunk.java
-index cc9c8b2e0..a59f5b190 100644
+index 62767a383..798522fa7 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 {