[system-administrators-guide] Removed files that are no longer used.

[jhradile]

commit 2f57424165dd9356fa7d6febf50fd196c4fb54cb
Author: Jaromir Hradilek <jhradilek at redhat.com>
Date:   Mon Oct 22 14:06:15 2012 +0200

    Removed files that are no longer used.

 en-US/RPM-Checking_Package_Signatures-Fedora.xml |   63 -
 en-US/RPM-Checking_Package_Signatures-RH.xml     |   66 -
 en-US/SSSD.xml                                   | 1906 ----------------------
 3 files changed, 0 insertions(+), 2035 deletions(-)