improved error message when a downloaded data is corrupted
improved error message when a downloaded data is corrupted

git-svn-id: 55bf3d274bcbe9e82fb62baa38e07bd3d37611b8@23655 651a555e-23ca-0310-84fe-ca9f7c59d2ea

cournape/ensetuptools,cournape/ensetuptools