package/autoconf-archive: bump to version 2021.02.19

Update indentation in hash file (two spaces)

https://git.savannah.gnu.org/cgit/autoconf-archive.git/tree/NEWS?h=v2021.02.19



Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>