patch 9.0.1793: obsolete macros in configure script

patch 9.0.1793: obsolete macros in configure script

Problem:  obsolete macros in configure script
Solution: Remove those and start moving to autoconf 2.71

src/configure.ac: Remove obsolete macros

These macros are declared obsolete in autoconf 2.69, which is almost 10
years old by now:

  https://www.gnu.org/software/autoconf/manual/autoconf-2.69/html_node/Obsolete-Macros.html

They generate warnings when in a subsequent upgrade to autoconf 2.71.

`autoupdate` from autoupdate 2.71 suggests most of these changes, except
that it also adds obsolete warnings, that where individually checked and
removed.

Regenerated `src/auto/configure` by running:

  cd src
  autoconf2.69 --output=auto/configure configure.ac
  sed --in-place --expression='s@>config.log@>auto/config.log@g' auto/configure

closes: #12888

Signed-off-by: Christian Brabandt <cb@256bit.org>
Co-authored-by: Illia Bobyr <illia.bobyr@gmail.com>