md5.c: Replace http URL to upstream version control with https one
md5.c has two http URLs. One comes from the upstream comment, so lets not change that until upstream does. The other, reference to upstream cvsweb, is our own comment. Update it to https URL.
md5.c has two http URLs. One comes from the upstream comment, so lets not change that until upstream does. The other, reference to upstream cvsweb, is our own comment. Update it to https URL.