Fix compile problem

QPointer was undefined (oddly I didn't run into this when test building
earlier).

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

qt-ui/printlayout.cpp

@@ -5,6 +5,7 @@
 #include <QApplication>
 #include <QTableView>
 #include <QHeaderView>
+#include <QPointer>
 #include "mainwindow.h"
 #include "../dive.h"
 #include "../display.h"