foliavalidator looses confidence

[kosloot]

using the example file: frog-deep.1.3.2.folia.xml

there is a section:

          <entity xml:id="example.deep.p.1.s.1.entities.1.entity.1" class="loc" confidence="0" set="https://raw.githubusercontent.com/proycon/folia/m
aster/setdefinitions/frog-ner-nl">
            <wref id="example.deep.p.1.s.1.w.2" t="Russen"/>
          </entity>

After parsing the confidence is lost!

          <entity xml:id="example.deep.p.1.s.1.entities.1.entity.1" set="https://raw.githubusercontent.com/proycon/folia/master/setdefinitions/frog-n
er-nl" class="loc">
            <wref id="example.deep.p.1.s.1.w.2" t="Russen"/>
          </entity>

[proycon]

Seems like 0 versus None confusion, but bug indeed, shouldn't get lost.