MainWindow: fixed removal of all feature sets so that the tab index changed slot is disconnected before. Fixes #1118

sdrgui/mainwindow.cpp

@@ -318,6 +318,8 @@ MainWindow::~MainWindow()
 	delete m_dateTimeWidget;
 	delete m_showSystemWidget;
 
+    disconnect(ui->tabFeatures, SIGNAL(currentChanged(int)), this, SLOT(tabFeaturesIndexChanged()));
+
     removeAllFeatureSets();
 
 	delete ui;