fix url-quote in URL handler
fix url-quote in URL handler

imsparsh/nbviewer,franblas/beaker-sharing-server,Sage-Bionetworks/nbviewer,Jay-Oh-eN/nbviewer,twosigma/beaker-sharing-server,thomasyu888/nbviewer,franblas/beaker-sharing-server,twosigma/beaker-sharing-server,twosigma/beaker-sharing-server,roxyboy/nbviewer,AlfiyaZi/nbviewer,twosigma/beaker-sharing-server,imsparsh/nbviewer,Jay-Oh-eN/nbviewer,franblas/beaker-sharing-server,bollwyvl/nbviewer,franblas/beaker-sharing-server,AlfiyaZi/nbviewer,christophelec/nbviewer,iamjakob/nbviewer,christophelec/nbviewer,roxyboy/nbviewer,iamjakob/nbviewer,thomasyu888/nbviewer,bollwyvl/nbviewer,Sage-Bionetworks/nbviewer