Follow-up from "Resolve "Add more intrinsic calibration parameters""

The following discussion from !150 (merged) should be addressed:

• @t.schroedter started a discussion: (+1 comment)

  This error now also shows when the a file is loaded, where all the values are set to 0. But this should only be displayed when a older file is loaded (<PETRACK VERSION="0.9.0"> and lower).