deleted unnecessary extra folder

Qt-application_for_UDP_broadcast/main.cpp

@@ -0,0 +1,11 @@
+#include "mainwindow.h"
+
+#include <QApplication>
+
+int main(int argc, char *argv[])
+{
+    QApplication a(argc, argv);
+    MainWindow w;
+    w.show();
+    return a.exec();
+}