bz#752559 - Disable the dialog on start

Reported ans accepted upstream as https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=6559

diff --git a/gtk/simple_dialog.c b/gtk/simple_dialog.c

index ff7d283..8ee40cf 100644

--- a/gtk/simple_dialog.c

+++ b/gtk/simple_dialog.c

@@ -316,10 +316,11 @@ vsimple_dialog(ESD_TYPE_E type, gint btn_mask, const gchar *msg_format, va_list

     state = gdk_window_get_state(top_level->window);

   }

-  /* If we don't yet have a main window or it's iconified, don't show the

-     dialog. If showing up a dialog, while main window is iconified, program

-     will become unresponsive! */

-  if (top_level == NULL || state & GDK_WINDOW_STATE_ICONIFIED) {

+  /* If we don't yet have a main window or it's iconified or hidden (i.e. not

+     yet ready, don't show the dialog. If showing up a dialog, while main

+     window is iconified, program will become unresponsive! */

+  if (top_level == NULL || state & GDK_WINDOW_STATE_ICONIFIED

+          || state & GDK_WINDOW_STATE_WITHDRAWN) {

     queued_message = g_malloc(sizeof (queued_message_t));

     queued_message->type = type;