support/gnuconfig: fix previous version bump

support/gnuconfig: fix previous version bump

Commit a2830f0dad7a (support/gnuconfig: bump version) carried
spurious, uncommited local changes to config.sub, that were not
part of upstream commit d7a4dee7cc25e332b990d0a6d9f0ddd42cb33cf5.

Fix that by actually using the code as it is upstream.

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
[yann.morin.1998@free.fr:
  - squash the revert and the new bump into this commit
  - ammend commit log accordingly
]
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>