setup storage can't use % or "G"

[James]

I've upgraded to the latest FAI with SETUP_STORAGE

i tried using the default SETUP_STORAGE disk layout but it doesn't like 
the lines that define like "4G" for 4 Gigabytes or 10% for 10% of disk
FAI will throw an error and says there's a problem with disk_setup 
configuration on the lines that contain those type of disk descriptions.

So i have to hard define disks like 500-4000 instead of 500-4G
or 500-4000 instead of 500-10%

TIA,
James