fix check for xrootd/lib as it can also be xrootd/lib64 (how? when?, wonders of cmake).
fix check for xrootd/lib as it can also be xrootd/lib64 (how? when?, wonders of
cmake).


git-svn-id: ecbadac9c76e8cf640a0bca86f6bd796c98521e3@41963 27541ba8-7e3a-0410-8455-c3a389f83636

dawehner/root,dawehner/root,dawehner/root,dawehner/root,dawehner/root,dawehner/root,dawehner/root,dawehner/root