Feature #4631: Staging and copyback
Copyback was using wrong url
For dcache and the third-party copy with srm-copy, you need to use full
SRM uri's; in this case, for Fermilab's dcache; its the
new value in 'srm://fndca1.fnal.gov:8443/srm/managerv2?SFN=/pnfs/fnal.gov/usr/fermigrid/volatile'
Thanks to Tanya Levshina for providing this