Fix "GtkSpinButton: setting an adjustment with non-zero page size is deprecated" warning.
Fix "GtkSpinButton: setting an adjustment with non-zero page size is deprecated" warning.

xfce-mirror/xfce4-genmon-plugin,dnschneid/xfce4-genmon-plugin,tonypaulic/xfce4-genmon-plugin,dnschneid/xfce4-genmon-plugin,xfce-mirror/xfce4-genmon-plugin,xfce-mirror/xfce4-genmon-plugin,tonypaulic/xfce4-genmon-plugin,dnschneid/xfce4-genmon-plugin,tonypaulic/xfce4-genmon-plugin