message: fix column parsing
diff: @@ -640,7 +640,7 @@ export function parseColumns(sharedString: SharedString, pos: number, table: Tab
  nextPos = segpos;
  if (segment.getType() === MergeTree.SegmentType.Marker) {
  let marker = <IColumnMarker>segment;
  - if (marker.columnId) {
  + if (marker.hasProperty("columnId")) {
  table.addGridColumn(marker);
  return true;
  }
  