[gtranslator/leo] Fix Help button in preferences dialog

[Daniel Garcia Moreno <danigm src gnome org>]

commit 3cfe6c44f8aead3ddf52a8760b1b4198192f2959
Author: Daniel García Moreno <dani danigm net>
Date:   Sat Oct 12 11:59:01 2019 +0200

    Fix Help button in preferences dialog
    
    Fix https://gitlab.gnome.org/GNOME/gtranslator/issues/32

 src/gtr-preferences-dialog.c | 3 +++
 1 file changed, 3 insertions(+)
---
diff --git a/src/gtr-preferences-dialog.c b/src/gtr-preferences-dialog.c
index 1be59013..cfa01176 100644
--- a/src/gtr-preferences-dialog.c
+++ b/src/gtr-preferences-dialog.c
@@ -587,6 +587,9 @@ dialog_response_handler (GtkDialog * dlg, gint res_id)
 {
   switch (res_id)
     {
+    case GTK_RESPONSE_HELP:
+      gtr_show_help (GTK_WINDOW (dlg));
+      break;
     default:
       gtk_widget_destroy (GTK_WIDGET (dlg));
     }