shared/unattended/RHEL-6.3.ks: Revert changes from 1ba831e1

Turns out the package libjpeg-turbo-devel could not be
found on the install DVD, causing trouble during regression
testing run. The changes need to be reverted until the
author can get a more precise listing.

Signed-off-by: Lucas Meneghel Rodrigues <lmr@redhat.com>