Do not log unrealistic disk usage (docker + macOS bug)

[DL6ER]

What does this implement/fix?

Do not log running out of disk space when the disk occupation is > 100%. We are seeing this with docker deployments on macOS hosts. It is a band-aid fix, however, it also seem to be the only thing we can do given that docker didn't fix this in nearly two years now.

This PR seeks to fix pi-hole/docker-pi-hole#951

Related issue or feature (if applicable): N/A

Pull request in docs with documentation (if applicable): N/A

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