Revert "Use redhat-lsb instead of redhat-lsb-core."

This reverts commit 53ec5d4d1aec4094b40e06f7be5f0183a954fe7f.

Turns out redhat-lsb-core was fine after all, as of a week ago:

    https://rhn.redhat.com/errata/RHBA-2013-0448.html

Change-Id: I8c258b084971bb090dc5d09645375939719a3259
Reviewed-on: https://review.openstack.org/23150
Reviewed-by: Khai Do <zaro0508@gmail.com>
Approved: James E. Blair <corvus@inaugust.com>
Reviewed-by: James E. Blair <corvus@inaugust.com>
Tested-by: Jenkins