Fix unacceptable kind of object to dump error

[scbedd]

When an example's reportedProperties attribute is NOT populated, you get an error that looks like this:

An example Failure

Last commit that eliminated this error

Effectively, I believe the issue is when we have objects with 0 value within the reportedProperties object on an example where they are being expected to be present, the error that is generated is just...wrong.

There's a PROBLEM here, we're expecting these examples to have some value here, but oav should just be reporting the missing expectations, rather than failing to dump the json.