added variable for efi partition

bootstrap-bookworm.sh

@@ -30,6 +30,7 @@ hostname="somehost.example.com"
 partition="single-mbr"
 disk="/dev/vda"  # lsblk --list
 disk1=$disk"1"
+disk0=$disk"p1"  # efi partion, only relevant if partion="efi"
 netDev="eth0"    # ip link
 netAddress="203.0.113.66/24"
 netGateway="203.0.113.1"