psconfig validate fails if empty host objects

[arlake228]

From Marian:

it looks like 5.1 update broke testing in our infrastructure and I was looking at it today and it looks like psconfig json is no longer recognized as valid, e.g.

psconfig validate --deep psconfig.opensciencegrid.org/pub/auto/psb02-gva.cern.ch

Loading config ...... OK
Validating JSON schema ...... OK
Verifying object references ...... FAIL

Address psonar9.fnal.gov references a host object psonar9.fnal.gov that does not exist.
Address psb02-gva.cern.ch references a host object psb02-gva.cern.ch that does not exist.
….

The hosts do have an entry in the "hosts" dictionary, but don't have any archive configure. For the psb02-gva.cern.ch case there is no archive as it's just a testpoint. This prevents psconfig agent to run and effectively removes all tests, so it impacts all perfSONARs that updated to 5.1, which use meshconfig from PWA.

Could you please check ?