HPCC-9766 Defaulting to "hthor" is often wrong

Fixes HPCC-9766

Signed-off-by: Gordon Smith <gordon.smith@lexisnexis.com>
Merge pull request #4681 from GordonSmith/HPCC-9766

HPCC-9766 Defaulting to "hthor" is often wrong

Reviewed-By: Miguel Vazquez <miguel.vazquez@lexisnexis.com>
Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>