Fix DISK_2 unbound variable.

deploy.sh

@@ -312,6 +312,7 @@ disks_selection() {
     echo -e "Consider using 2 boot disks instead to get data protection features on the boot disks."
     export BOOT_DISK_1_ID="${BOOT_DISKS_ID[0]}"
     export BOOT_DISK_1_NAME="${BOOT_DISKS_NAME[0]}"
+    export BOOT_DISK_2_NAME=""
   elif [[ "${#BOOT_DISKS_ID[@]}" -eq 2 ]]; then
     echo -e "\n\n ✅ Two boot disks selected, continuing with mirrored boot disks configuration."
     echo -e "\n\n ⚠️ If the two disks are different sizes, the resulting usable space size will be \
@@ -884,8 +885,6 @@ sed -i "s|#  systemIdentity.pcr15 = "PCR_HASH";|  systemIdentity.pcr15 = "PCR_HA
 sed -i "s|PCR_HASH|\${PCR_HASH}|" /etc/nixos/configuration.nix
 EOF
 
-
-
   gum style --border normal --margin "1" --padding "1 2" --border-foreground 212 "
   ⚠️  $(gum style --foreground 212 'WARNING:') You will now set the password of the numbus-admin user. \
 You will almost never user it. Consider using a very strong password : you can write it down \