[Kst] [Kst-plot/kst] ad4584: fix crash, nothing to do with no plots

[Peter Kümmel]

  Branch: refs/heads/master
  Home:   https://github.com/Kst-plot/kst
  Commit: ad4584d803fe451e8f80652204c82cba11f80a97
      https://github.com/Kst-plot/kst/commit/ad4584d803fe451e8f80652204c82cba11f80a97
  Author: Peter Kümmel <syntheticpp at gmx.net>
  Date:   2013-09-25 (Wed, 25 Sep 2013)

  Changed paths:
    M src/libkstapp/datawizard.cpp

  Log Message:
  -----------
  fix crash, nothing to do with no plots