Bump version of selinux module

The 0.5.0 selinux module we initially installed had a dangling
symlink bug. Upstream has fixed this in 0.5.1.

Change-Id: Ia286eb39de3ded7d407f2875fcce79f834a82aca
Reviewed-on: https://review.openstack.org/36569
Reviewed-by: Clark Boylan <clark.boylan@gmail.com>
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