Revert "Only the main window and its childs should be native widgets"

This reverts commit fe3aab2a0e.

src/qt/qt_main.cpp

@@ -176,6 +176,7 @@ main(int argc, char *argv[])
 
 #ifdef Q_OS_WINDOWS
     Q_INIT_RESOURCE(darkstyle);
+    QApplication::setAttribute(Qt::AA_NativeWindows);
 
     if (!windows_is_light_theme()) {
         QFile f(":qdarkstyle/dark/darkstyle.qss");