Boot TrueNAS from its disk, not from the installer ISO

qm create was called without a boot order, so Proxmox fell back to its
default and put the CD-ROM first. The install completes, the VM reboots,
and the installer comes up again.

sata0 first, ide2 behind it: an empty disk still falls through to the ISO
for the initial install, and every boot after that finds the system. This
was the only vm/ script with no boot order and the only one using -cdrom.

vm/truenas-vm.sh

@@ -578,7 +578,8 @@ qm create "$VMID" -machine q35 -bios ovmf -agent enabled=1 -tablet 0 -localtime
   -cores "$CORE_COUNT" -memory "$RAM_SIZE" -balloon 0 -name "$HN" -tags community-script \
   -net0 "virtio,bridge=$BRG,macaddr=$MAC$VLAN$MTU" -onboot 1 -ostype l26 \
   -efidisk0 $STORAGE:1,efitype=4m,pre-enrolled-keys=0 -sata0 $STORAGE:$DISK_SIZE,ssd=1 \
-  -scsihw virtio-scsi-single -cdrom local:iso/$ISO_NAME -vga virtio >/dev/null
+  -scsihw virtio-scsi-single -cdrom local:iso/$ISO_NAME -vga virtio \
+  -boot order='sata0;ide2' >/dev/null
 msg_ok "Created VM shell"
 
 if [ "$IMPORT_DISKS" == "yes" ]; then