[gparted] Use Gtk::Box for Dialog_DiskLabel (!25)

[Mike Fleetwood <mfleetwo src gnome org>]

commit 85ab57fee6860049bee2412934cbdd8eede4234b
Author: Luca Bacci <luca bacci982 gmail com>
Date:   Wed Feb 27 16:38:15 2019 +0100

    Use Gtk::Box for Dialog_DiskLabel (!25)
    
    Gtk::HBox and Gtk::VBox were deprecated in Gtkmm 3.2.  Replace with
    plain Gtk::Box.
    
    This commit makes the change for Dialog_DiskLabel.cc.
    
    Closes !25 - Modern Gtk3 - part 1

 src/Dialog_Disklabel.cc | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)
---
diff --git a/src/Dialog_Disklabel.cc b/src/Dialog_Disklabel.cc
index 1f89dfed..09926ffe 100644
--- a/src/Dialog_Disklabel.cc
+++ b/src/Dialog_Disklabel.cc
@@ -32,11 +32,11 @@ Dialog_Disklabel::Dialog_Disklabel( const Device & device )
        this ->set_resizable( false );
 
        {
-               Gtk::HBox* hbox(manage(new Gtk::HBox()));
+               Gtk::Box *hbox(manage(new Gtk::Box(Gtk::ORIENTATION_HORIZONTAL)));
 
                get_vbox()->pack_start(*hbox, Gtk::PACK_SHRINK);
 
-               Gtk::VBox* vbox(manage(new Gtk::VBox()));
+               Gtk::Box *vbox(manage(new Gtk::Box(Gtk::ORIENTATION_VERTICAL)));
 
                vbox->set_border_width(10);
                hbox->pack_start(*vbox, Gtk::PACK_SHRINK);
@@ -44,7 +44,7 @@ Dialog_Disklabel::Dialog_Disklabel( const Device & device )
                Gtk::Image* image(Utils::mk_image(Gtk::Stock::DIALOG_WARNING, Gtk::ICON_SIZE_DIALOG));
                vbox->pack_start(*image, Gtk::PACK_SHRINK);
 
-               vbox = manage(new Gtk::VBox());
+               vbox = manage(new Gtk::Box(Gtk::ORIENTATION_VERTICAL));
                vbox->set_border_width(10);
                hbox->pack_start(*vbox, Gtk::PACK_SHRINK);
 
@@ -56,7 +56,7 @@ Dialog_Disklabel::Dialog_Disklabel( const Device & device )
                        str_temp += "</span>\n";
                        vbox->pack_start(*Utils::mk_label(str_temp), Gtk::PACK_SHRINK);
 
-                       hbox = manage(new Gtk::HBox(false, 5));
+                       hbox = manage(new Gtk::Box(Gtk::ORIENTATION_HORIZONTAL, 5));
                        hbox->set_border_width(5);
                        str_temp = _("Select new partition table type:");
                        str_temp += "\t";