Fixed crash

source/ubinstall-gtk-page-switch.c

@@ -494,6 +494,8 @@ void on_page_cancel_clicked(GtkWidget *, main_window *widgets){
                 data->title=WARNING_TITLE_LABEL;
                 if (yon_confirmation_dialog_call(widgets->MainWindow,data)==GTK_RESPONSE_ACCEPT ){
                     pthread_cancel(main_config.install_thread);
+                    g_file_monitor_cancel(widgets->install_progress_monitor);
+                    widgets->install_progress_monitor = NULL;
                     gtk_button_set_label(GTK_BUTTON(widgets->NextButton),NEXT_LABEL);
                     GtkWidget *image = gtk_button_get_image(GTK_BUTTON(widgets->NextButton));
                     gtk_image_set_from_icon_name(GTK_IMAGE(image),arrow_right_icon_path,GTK_ICON_SIZE_BUTTON);