sys-apps/selinux-python: Have dependency blocker on older policycoreutils versions

sys-apps/selinux-python: Have dependency blocker on older policycoreutils versions

The selinux-python package can only be installed after policycoreutils has been
upgraded. To accomplish that, a PDEPEND was put in place in policycoreutils.
However, in some situations Portage does not want to use this ordering. This
is expected behavior, because PDEPEND does not necessarily mean that the
package manager has to install it afterwards - it is just a notion that the
order doesn't matter.

In this case, it does. So in order to ensure that the order is maintained,
we add in a blocker dependency on the older policycoreutils in selinux-python.

See also bug 622102

Package-Manager: Portage-2.3.5, Repoman-2.3.1