benchmark/bm_so_lists.rb: address the broken link; close
The original page was lost, so we added the link to the wayback machine.
# from http://www.bagley.org/~doug/shootout/bench/lists/lists.ruby
+# which is lost long time ago. The past content can be retrieved from
+# https://web.archive.org/web/20040805115204/http://www.bagley.org/~doug/shootout/bench/lists/lists.ruby
NUM = 300
SIZE = 10000
