Fix token assumption in authorized_upload
Fix token assumption in authorized_upload

The authorized_upload plugin was incorrectly assuming that
anything going through the upload model layer would have a
token returned by getCurrentToken(). This is not true, with
the thumbnail generation job being a notable exception.

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