[Kst-plot/kst] 2d4752: Fix windows build.

[Barth Netterfield]

  Branch: refs/heads/master
  Home:   https://github.com/Kst-plot/kst
  Commit: 2d4752c0266d4dd7738715665cf3adaf99fbb77a
      https://github.com/Kst-plot/kst/commit/2d4752c0266d4dd7738715665cf3adaf99fbb77a
  Author: Barth Netterfield <netterfield at astro.utoronto.ca>
  Date:   2017-02-08 (Wed, 08 Feb 2017)

  Changed paths:
    M src/libkstapp/labelrenderer.cpp

  Log Message:
  -----------
  Fix windows build.