- make sure the default ip rules are preserved over network restart

- make sure the default ip rules are preserved over network restart
  even if 'ip rule show' displays them using numeric table values.
  I have a system where 'from all lookup 255' is returned instead of
  'from all lookup local' for unknown reason, but it could also happen
  if /etc/iproute2/rt_tables file is missing or corrupted. And bad things
  happen (IPv4 not working) if the 'lookup local' rule is missing.

svn-id: @12228