Prepare for reusing libvirtd socket unit files with other daemons by
making various parts of their config conditionally defined by the make
rules.
Reviewed-by: Christophe de Dinechin <dinechin@redhat.com>
Reviewed-by: Andrea Bolognani <abologna@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>