package/perl: fix README hash

package/perl: fix README hash

Commit d5c7c9dabb94d64855b8c0383e77d01b890f85c3 forgot to update README
hash (year, github issue tracker):
https://github.com/Perl/perl5/commit/9802995490251df92faf7a0dd5c7114ad8146bd3
https://github.com/Perl/perl5/commit/b9e2183386fadc0979b46e024365ceab56a369aa

Also update indentation (two spaces)

Fixes:
 - http://autobuild.buildroot.org/results/3b124aca123207460a9d025f5afd23f5f67fbf18

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>