Fix fstab Before the Next Reboot

This server reboots tonight. Two problems in /etc/fstab need fixing first.

Task

• Add the new data volume: the filesystem with UUID 3f1c2a9e-5b7d-4e11-9c0a-8d2e6f4b7a10 (ext4) must be mounted at /srv/inventory with the options defaults,noatime, dump 0, fsck pass 2. The mount point must exist.
• The NFS share backup.internal:/exports/inventory already has a line. When the backup server is down, it stops the boot. Make the boot carry on without it, and make sure it is only mounted once the network is up. Keep its existing options.
• Leave every other line as it is.