[Kst-plot/kst] be7f45: Fix windows build.

[Barth Netterfield]

Branch: refs/heads/master
Home: https://github.com/Kst-plot/kst
Commit: be7f45a9a526ed2fe9320e87dc0a3030eb4d99f5
https://github.com/Kst-plot/kst/commit/be7f45a9a526ed2fe9320e87dc0a3030eb4d99f5
Author: Barth Netterfield <***@astro.utoronto.ca>
Date: 2016-12-22 (Thu, 22 Dec 2016)

Changed paths:
M src/libkstmath/psdcalculator.h

Log Message:
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Fix windows build.