Objectstore GC Repack unit tests rely on a specific string in an exception message.

Removed the changelog entries for 4.0-2 from cta.spec.in.  The updated version of these should be put back when the next release is made

Refactors XrootCl.cpp to sanitise value returned by
`XrdCl::XRootDStatus::ToStr()`

[cta-taped] Added a specific error message when the drive device file is not found when a drive is set UP

[Repack] The repack subrequests are queued by batch of 500. They are also deleted by batch of 500 when the repack request is deleted

Fixed.