[balsa/gtk4: 143/298] balsa-mime-widget: Use container-add for buttons

[Peter Bloomfield <peterb src gnome org>]

commit 81afd342ce55a9614969cedf9ab501efcf9d414a
Author: Peter Bloomfield <PeterBloomfield bellsouth net>
Date:   Sun Aug 23 16:33:31 2020 -0400

    balsa-mime-widget: Use container-add for buttons
    
    instead of box-pack-start, so that hexpand is respected.

 src/balsa-mime-widget.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/src/balsa-mime-widget.c b/src/balsa-mime-widget.c
index a66320097..f91912c98 100644
--- a/src/balsa-mime-widget.c
+++ b/src/balsa-mime-widget.c
@@ -267,7 +267,7 @@ balsa_mime_widget_new_unknown(BalsaMessage * bm,
                                            (gpointer) mime_body))) {
         gtk_widget_set_hexpand(button, TRUE);
         gtk_widget_set_halign(button, GTK_ALIGN_FILL);
-       gtk_box_pack_start(GTK_BOX(hbox), button, FALSE, FALSE, 0);
+        gtk_container_add(GTK_CONTAINER(hbox), button);
     } else {
        gtk_box_pack_start(GTK_BOX(mw),
                           gtk_label_new(_("No open or view action "
@@ -279,7 +279,7 @@ balsa_mime_widget_new_unknown(BalsaMessage * bm,
     button = gtk_button_new_with_mnemonic(_("S_ave part"));
     gtk_widget_set_hexpand(button, TRUE);
     gtk_widget_set_halign(button, GTK_ALIGN_FILL);
-    gtk_box_pack_start(GTK_BOX(hbox), button, FALSE, FALSE, 0);
+    gtk_container_add(GTK_CONTAINER(hbox), button);
     g_signal_connect(button, "clicked",
                     G_CALLBACK(balsa_mime_widget_ctx_menu_save),
                     (gpointer) mime_body);