[GRASS-git] [OSGeo/grass] 341370: configure: update to autoconf 2.69 (#1867)

[nilason]

  Branch: refs/heads/releasebranch_7_8
  Home:   https://github.com/OSGeo/grass
  Commit: 341370e4627c3b85c8805bd8d7ad926af88013e0
      https://github.com/OSGeo/grass/commit/341370e4627c3b85c8805bd8d7ad926af88013e0
  Author: nilason <n_larsson at yahoo.com>
  Date:   2021-09-14 (Tue, 14 Sep 2021)

  Changed paths:
    M aclocal.m4
    M config.guess
    M config.sub
    M configure
    M configure.in
    M include/Makefile
    M include/config.h.in
    M lib/calc/calc.c
    M lib/gis/env.c
    M lib/gis/pager.c
    M lib/manage/sighold.c
    M mswindows/osgeo4w/config.h.vc

  Log Message:
  -----------
  configure: update to autoconf 2.69 (#1867)

Manual backport of #1845