[gtk] Exit cleanly if no display is found

[Matthias Clasen <matthiasc src gnome org>]

commit da8e83f9cb268173aa006f5c631f5c2b56f4858f
Author: Matthias Clasen <mclasen redhat com>
Date:   Sun Mar 11 08:14:14 2018 -0400

    Exit cleanly if no display is found
    
    We should not try to create an inspector window and generate
    tons of ugly warnings in this case.

 gtk/gtkmain.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/gtk/gtkmain.c b/gtk/gtkmain.c
index 395a470c57..336c9363ae 100644
--- a/gtk/gtkmain.c
+++ b/gtk/gtkmain.c
@@ -777,7 +777,7 @@ gtk_init_check (void)
 
   ret = gdk_display_open_default () != NULL;
 
-  if (gtk_get_debug_flags () & GTK_DEBUG_INTERACTIVE)
+  if (ret && (gtk_get_debug_flags () & GTK_DEBUG_INTERACTIVE))
     gtk_window_set_interactive_debugging (TRUE);
 
   return ret;