Fix MSVC++ compile error caused by missing round() in math.h

cockatrice/src/pixmapgenerator.cpp

@@ -2,7 +2,10 @@
 #include "pb/serverinfo_user.pb.h"
 #include <QPainter>
 #include <QSvgRenderer>
-#include <math.h>
+#include <cmath>
+#ifdef _WIN32
+#include "round.h"
+#endif /* _WIN32 */
 #include <QDebug>
 
 QMap<QString, QPixmap> PhasePixmapGenerator::pmCache;