bootstrap.SetupNodeDaemon: Stop hardcoding bind address

Commit b43dcc5a added support for IPv6. To have the node daemon bind
to an IPv6 address on startup it changed the code to pass a static bind
address (0.0.0.0 or ::0). If a user had configured another bind address
using /etc/default/ganeti, that address would not be used until the
daemons were restarted.

By copying ssconf files before attempting to start the daemons we can
ensure that the built-in IP family detection in daemon.py works.

This fixes issue 267.

Signed-off-by: Michael Hanselmann <hansmi@google.com>
Reviewed-by: René Nussbaumer <rn@google.com>