Merge pull request #2774 from Cacodemon345/qt-white-screen-fix

qt: make background of main window black

src/qt/qt_mainwindow.cpp

@@ -154,6 +154,7 @@ MainWindow::MainWindow(QWidget *parent) :
     ui->stackedWidget->setMouseTracking(true);
     statusBar()->setVisible(!hide_status_bar);
     statusBar()->setStyleSheet("QStatusBar::item {border: None; } QStatusBar QLabel { margin-right: 2px; margin-bottom: 1px; }");
+    this->setStyleSheet("#centralWidget { background-color: black; }");
     ui->toolBar->setVisible(!hide_tool_bar);
     renderers[0].reset(nullptr);
     auto toolbar_spacer = new QWidget();