Revert "Enable build of slurm debuginfo packages"

This reverts commit 2deeaf82d4b4093a430013d0974113a42a73a30e.

Apparently there is no way with RPM to create debuginfo packages and
_not_ strip all debug symbols. So just revert the commit above to
avoid confusing debuggers like TotalView.
Updates for slurm-2.3.3-1.13chaos