libpcap: updated to 1.10.4

Summary for 1.10.4 libpcap release
  Source code:
    Fix spaces before tabs in indentation.
  rpcap:
    Fix name of launchd service.
  Documentation:
    Document use of rpcapd with systemd, launchd, inetd, and xinetd.
  Building and testing:
    Require at least pkg-config 0.17.0, as we use --static.
    Get rid of the remains of gnuc.h.
    Require at least autoconf 2.69.
    Update config.{guess,sub}, timestamps 2023-01-01,2023-01-21.

(adam)