Fix: avoid sid=none in JSON output

[AdrianVollmer]

I had an issue with the output files. Bloodhound would fail when importing. The message in the dev console said something like Cannot read property of null.

I found that the computers.json contained lines like this:

       "AllowedToDelegate": [
            "S-1-XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX",
             null
      ],

This patch makes sure to add sids to the AllowedToDelegate list only if they are not Null (or empty).

I reckon this happens when the SID is from another domain.

[Relkci]

tested and confirmed fix allows data to be ingested correctly.

[adindrabkin]

These edits patch the BloodHound freezing issue but unintentionally result in incomplete data output. I opened a new PR that fixes the underlying issue, see #16.

[c3c]

thanks for making this change, closing it in favour of #16