XRootD fix, master branch (2017.03.29.)
This is a cherry pick of !18 (merged). Pushing the same fix of FindXrootd.cmake
into the master branch as well. Fixing ATLINFR-1631 for the master builds.
This is a cherry pick of !18 (merged). Pushing the same fix of FindXrootd.cmake
into the master branch as well. Fixing ATLINFR-1631 for the master builds.