Update nextcloud-vm.sh to 18.1 ISO (#3333)

New 18.1 ISO File on turnkey!

Author: mxwmnn

vm/nextcloud-vm.sh

@@ -386,7 +386,7 @@ fi
 msg_ok "Using ${CL}${BL}$STORAGE${CL} ${GN}for Storage Location."
 msg_ok "Virtual Machine ID is ${CL}${BL}$VMID${CL}."
 msg_info "Retrieving the URL for the $NAME Disk Image"
-URL=http://mirror.turnkeylinux.org/turnkeylinux/images/iso/turnkey-nextcloud-18.0-bookworm-amd64.iso
+URL=http://mirror.turnkeylinux.org/turnkeylinux/images/iso/turnkey-nextcloud-18.1-bookworm-amd64.iso
 sleep 2
 msg_ok "${CL}${BL}${URL}${CL}"
 wget -q --show-progress $URL