MFC r255056
  Reduce WARNS to 0 for dig, host, and nslookup to make them
  compile with the optional WITH_BIND_SIGCHASE.

  Submitted by: Andre Albsmeier <Andre.Albsmeier@siemens.com>
  Approved by:  delphij (mentor, implicit)
  Sponsored by: DK Hostmaster A/S