[gthumb] use menus instead of popovers for menu buttons on the header bar

[Paolo Bacchilega <paobac src gnome org>]

commit 74ca333250f0548c5fb460b123062c46da66e6c9
Author: Paolo Bacchilega <paobac src gnome org>
Date:   Sun Oct 20 11:44:57 2019 +0200

    use menus instead of popovers for menu buttons on the header bar
    
    Popovers do not show accelerators and icons.

 gthumb/gtk-utils.c | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/gthumb/gtk-utils.c b/gthumb/gtk-utils.c
index 861b04f3..28897fcf 100644
--- a/gthumb/gtk-utils.c
+++ b/gthumb/gtk-utils.c
@@ -938,6 +938,7 @@ _gtk_menu_button_new_for_header_bar (const char *icon_name)
        GtkWidget *button;
 
        button = gtk_menu_button_new ();
+       gtk_menu_button_set_use_popover (GTK_MENU_BUTTON (button), FALSE);
        if (icon_name != NULL) {
                GtkWidget *image;