https:// for translatable gnu.org URL
There's just one "http://" in the translatable strings of S3_0 core domain. That's for gnu.org, and "https://" works, so change it.
Update all gnu.org http URLs to https ones, not just the one in translatable string.
There's just one "http://" in the translatable strings of S3_0 core domain. That's for gnu.org, and "https://" works, so change it.