Fix regression introduced by b9d6b628a98fc17f5e92a344450b6336f1a2b2ce
Fix regression introduced by b9d6b628a98fc17f5e92a344450b6336f1a2b2ce

When calculated the palette height based in the size of children,
forgoten add the border size. That moved the palette in the device icons
4 pixels to the bottom, then the gap was miscalcuated and the border
button border was not draw.

Signed-off-by: Gonzalo Odiard <aef65ed16d0ea9f2366d05ae21f0b27430ef2e79@sugarlabs.org>

godiard/sugar-toolkit-gtk3,puneetgkaur/backup_sugar_sugartoolkit,quozl/sugar-toolkit-gtk3,Daksh/sugar-toolkit-gtk3,i5o/sugar-toolkit-gtk3,puneetgkaur/sugar-toolkit-gtk3,puneetgkaur/sugar-toolkit-gtk3,sugarlabs/sugar-toolkit-gtk3,puneetgkaur/sugar-toolkit-gtk3,sugarlabs/sugar-toolkit-gtk3,Daksh/sugar-toolkit-gtk3,i5o/sugar-toolkit-gtk3,tchx84/sugar-toolkit-gtk3,puneetgkaur/backup_sugar_sugartoolkit,quozl/sugar-toolkit-gtk3,tchx84/debian-pkg-sugar-toolkit-gtk3,tchx84/debian-pkg-sugar-toolkit-gtk3,Daksh/sugar-toolkit-gtk3,tchx84/sugar-toolkit-gtk3,quozl/sugar-toolkit-gtk3,i5o/sugar-toolkit-gtk3,i5o/sugar-toolkit-gtk3,tchx84/debian-pkg-sugar-toolkit-gtk3,quozl/sugar-toolkit-gtk3,godiard/sugar-toolkit-gtk3,godiard/sugar-toolkit-gtk3,puneetgkaur/backup_sugar_sugartoolkit,sugarlabs/sugar-toolkit-gtk3,tchx84/sugar-toolkit-gtk3