spicy: Avoid gtk_vbox_new(); it is deprecated
spicy: Avoid gtk_vbox_new(); it is deprecated

Spice-Gtk requires GTK+ > 3.12 which has gtk_box_new().

Signed-off-by: Francois Gouget <6b915da68578f6eb004fe99432b967565fc9be8f@codeweavers.com>
Acked-by: Jonathon Jongsma <c7254805a17bd5c41e24c3a278fcbf3afcdfb0fa@redhat.com>

flexVDI/spice-gtk,fgouget/spice-gtk,fgouget/spice-gtk,fgouget/spice-gtk,flexVDI/spice-gtk