o Minor bugfixes (Linux seccomp2 sandbox):
    - Add a few missing syscalls to the seccomp2 sandbox: sysinfo,
      getsockopt(SO_SNDBUF), and setsockopt(SO_SNDBUFFORCE). On
      some systems, these are required for Tor to start with
      "Sandbox 1" enabled.
      Fixes bug 18397; bugfix on 0.2.5.1-alpha. Patch from
      Daniel Pinto.