Prepare for reusing libvirtd config to create other daemons by making
the config parameters for IP sockets conditionally defined by the make
rules.

The main libvirtd daemon will retain IP listen ability, but all the
driver specific daemons will be local UNIX sockets only. Apps needing
IP connectivity will connect via the libvirtd daemon which will proxy
to the driver specfic daemon.
Reviewed-by: NChristophe de Dinechin <dinechin@redhat.com>
Reviewed-by: NAndrea Bolognani <abologna@redhat.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>