[InterNetNews/inn] 6efd10: Update to latest rra-c-util upstream version

[Julien ÉLIE]

  Branch: refs/heads/main
  Home:   https://github.com/InterNetNews/inn
  Commit: 6efd10305986cb71399781d0cb04ef7d51bd195f
      https://github.com/InterNetNews/inn/commit/6efd10305986cb71399781d0cb04ef7d51bd195f
  Author: Julien ÉLIE <Julien-Elie at users.noreply.github.com>
  Date:   2021-12-19 (Sun, 19 Dec 2021)

  Changed paths:
    M include/portable/system.h
    M lib/getnameinfo.c
    M m4/socket.m4

  Log Message:
  -----------
  Update to latest rra-c-util upstream version

- Fix IN6_ARE_ADDR_EQUAL_SOURCE probe on macOS Monterey.

- Ignore -Wformat-truncation only for GCC 7 and later (it was not defined
in earlier versions).