export-image: increase free space padding
export-image: increase free space padding

KingBrewer/pi-gen,rkubes/pi-gen,BlokasLabs/modep,DigitaleGesellschaft/pi-gen,timcoote/Pumpkin-gen,drothmaler/pi-gen,WLANThermo/pi-gen,8devices/pi-gen,timcoote/Pumpkin-gen,BlokasLabs/modep,jacen92/pi-gen,barnacleos/build,cfstras/pi-gen,brindosch/pi-gen,timcoote/Pumpkin-gen,RPi-Distro/pi-gen