empty token is changed to nil when removing_token
empty token is changed to nil when removing_token

CDLUC3/dmptool,DigitalCurationCentre/roadmap,DMPRoadmap/roadmap,CDLUC3/dmptool,DMPRoadmap/roadmap,DMPRoadmap/roadmap,DigitalCurationCentre/roadmap,CDLUC3/dmptool,CDLUC3/dmptool,DigitalCurationCentre/roadmap