Use direct chunk access for neighbour counts on unload

nms-patches/ChunkProviderServer.patch

@@ -160,7 +160,7 @@
 +                                    continue;
 +                                }
 +
-+                                Chunk neighbor = this.getLoadedChunkAt(chunk.locX + x, chunk.locZ + z);
++                                Chunk neighbor = this.chunks.get(ChunkCoordIntPair.a(chunk.locX + x, chunk.locZ + z));
 +                                if (neighbor != null) {
 +                                    neighbor.setNeighborUnloaded(-x, -z);
 +                                    chunk.setNeighborUnloaded(x, z);