Reverted pull requestion no. 2775.

src/qt/qt_mainwindow.hpp

@@ -5,8 +5,6 @@
 #include <QLabel>
 #include <QEvent>
 #include <QFocusEvent>
-#include <QPainter>
-#include <QStatusBar>
 
 #include <memory>
 #include <array>
@@ -130,15 +128,6 @@ protected:
     void showEvent(QShowEvent* event) override;
     void closeEvent(QCloseEvent* event) override;
     void changeEvent(QEvent* event) override;
-    void paintEvent(QPaintEvent* event) override
-    {
-        QPainter painter(this);
-#if QT_VERSION >= QT_VERSION_CHECK(5, 14, 0)
-        painter.fillRect(0, 0, this->width(), this->height() - statusBar()->height(), QColorConstants::Black);
-#else
-        painter.fillRect(0, 0, this->width(), this->height() - statusBar()->height(), Qt::black);
-#endif
-    }
 
 private slots:
     void on_actionShow_non_primary_monitors_triggered();