apply "skipEmptyHistograms" tag also to data individually
Release notes
The "skipEmptyHistograms" tag of TQROOTPlotter
now also applies to data histograms individually.
Therefore, no markers are drawn if there are no data events in the histogram.
Details
As discussed on the mailing list: https://groups.cern.ch/group/qframework-users/Lists/Archive/Flat.aspx?RootFolder=%2Fgroup%2Fqframework%2Dusers%2FLists%2FArchive%2Fdon%27t%20plot%20histogram%20markers%20for%20processes%20without%20events&FolderCTID=0x01200200BC70EC9B4B3D9548A2F698081355FE39