SPIGOT-2282: Get loaded chunk

By: md_5 <git@md-5.net>

paper-server/nms-patches/ChunkProviderServer.patch

@@ -46,6 +46,7 @@
      }
  
      public Chunk getChunkAt(int i, int j) {
+-        Chunk chunk = this.getOrLoadChunkAt(i, j);
 +        return getChunkAt(i, j, null);
 +    }
 +
@@ -82,7 +83,7 @@
 +    }
 +
 +    public Chunk originalGetChunkAt(int i, int j) {
-         Chunk chunk = this.getOrLoadChunkAt(i, j);
++        Chunk chunk = this.getLoadedChunkAt(i, j);
 +        boolean newChunk = false;
 +        // CraftBukkit end