Fix hasdbxref

[Robbie1977]

Still some issues from curation loading into KB. Hopefully, this closes all the issues.

[Robbie1977]

FYI I've manually fixed the latest curation xrefs added over the last month.

[dosumis]

This one might go round forever. The problem is down to whether this has a label in input ontologies (=> de facto standard label => database_cross_reference as edge name) or not (=> hasDbXref as edge name). I think we've gone back and forth on a solution. Do avoid churn, it might be best to ensure that this label is injected via VFB_ext.owl and that we have a test in place to stop any variants on this creeping in.

[Clare72]

label is already in vfbext:

    <owl:AnnotationProperty rdf:about="http://www.geneontology.org/formats/oboInOwl#hasDbXref">
        <rdfs:label>database_cross_reference</rdfs:label>
    </owl:AnnotationProperty>

[dosumis]

label is already in vfbext

OK. Should all be good then. Not sure why the test is failing.