[gnome-dictionary/preferences-modal] Make the preference dialog modal to the app window

[Emmanuele Bassi <ebassi src gnome org>]

commit 2fedb5a5350e21fd524e08ebd64d79b0f8a59e33
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Fri Sep 25 17:38:05 2020 +0100

    Make the preference dialog modal to the app window
    
    There's no point in making the dialog free-floating.

 src/gdict-pref-dialog.c | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/src/gdict-pref-dialog.c b/src/gdict-pref-dialog.c
index 632ffa7..886984a 100644
--- a/src/gdict-pref-dialog.c
+++ b/src/gdict-pref-dialog.c
@@ -624,6 +624,7 @@ gdict_show_pref_dialog (GtkWidget         *parent,
         {
           gtk_window_set_transient_for (GTK_WINDOW (dialog), GTK_WINDOW (parent));
           gtk_window_set_destroy_with_parent (GTK_WINDOW (dialog), TRUE);
+          gtk_window_set_modal (GTK_WINDOW (dialog), TRUE);
           g_object_set_data_full (G_OBJECT (parent), "gdict-pref-dialog",
                                   dialog,
                                   g_object_unref);