webadmin: Add selinux state to host general subtab

Add selinux enforce mode display to host general subtab

Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=894084
Change-Id: If8067594169e46f8b09cc8b6247660da6e10de80
Signed-off-by: Dima Kuznetsov <dkuznets@redhat.com>