message: fix segfault when tracker does not find tracks in one sector
diff: @@ -278,7 +278,7 @@ void AliHLTTPCGMMerger::UnpackSlices()
  for( int i=0; i<fgkNSlices; i++)
  {
  firstGlobalTracks[i] = 0;
  - if (fkSlices[i]->NLocalTracks() > maxSliceTracks) maxSliceTracks = fkSlices[i]->NLocalTracks();
  + if (fkSlices[i] && fkSlices[i]->NLocalTracks() > maxSliceTracks) maxSliceTracks = fkSlices[i]->NLocalTracks();
  }
  int* TrackIds = new int[maxSliceTracks * fgkNSlices];
  