Change qt header inclusion syntax

AdaptiveBrightness/AdaptiveBrightness.cpp

@@ -1,5 +1,7 @@
 #include "AdaptiveBrightness.hpp"
 
+#include <QMessageBox>
+
 AdaptiveBrightness::AdaptiveBrightness(QWidget* parent) : QMainWindow(parent)
 {
     m_ui.setupUi(this);

AdaptiveBrightness/main.cpp

@@ -1,4 +1,4 @@
-#include <QtWidgets/QApplication>
+#include <QApplication>
 
 #include "AdaptiveBrightness.hpp"