message: Sub dataset fixup
diff: @@ -58,8 +58,10 @@ struct SubDataset::Itl
  Chunk mainChunk;
  std::mutex recordLock;
  + MldbServer * owner;
  Itl(SelectStatement statement, MldbServer* owner, const ProgressFunc & onProgress)
  + : owner(owner)
  {
  if (statement.from) {
  SqlExpressionMldbScope mldbContext(owner);
  @@ -72,21 +74,19 @@ struct SubDataset::Itl
  }
  }
  - Itl(MldbServer * server,
  + Itl(MldbServer * owner,
  std::vector<NamedRowValue> rows)
  - : server(server)
  + : owner(owner)
  {
  init(std::move(rows));
  }
  - MldbServer * server;
  -
  struct ChunkRecorder: public Recorder {
  Chunk myChunk;
  ChunkRecorder(Itl * itl)
  - : Recorder(itl->server),
  + : Recorder(itl->owner),
  itl(itl)
  {
  }
  