Fix a bug in the special "_id" case in Model._removeSupplementalFields
Fix a bug in the special "_id" case in Model._removeSupplementalFields

Xarthisius/girder,jbeezley/girder,kotfic/girder,manthey/girder,Kitware/girder,RafaelPalomar/girder,Xarthisius/girder,girder/girder,kotfic/girder,Xarthisius/girder,jbeezley/girder,kotfic/girder,data-exp-lab/girder,girder/girder,RafaelPalomar/girder,manthey/girder,Kitware/girder,Kitware/girder,RafaelPalomar/girder,manthey/girder,RafaelPalomar/girder,manthey/girder,kotfic/girder,RafaelPalomar/girder,kotfic/girder,jbeezley/girder,data-exp-lab/girder,data-exp-lab/girder,Xarthisius/girder,girder/girder,jbeezley/girder,Kitware/girder,data-exp-lab/girder,Xarthisius/girder,data-exp-lab/girder,girder/girder