Change keroserene.net/snowflake to snowflake.torproject.org now that [#23947](https://trac.torproject.org/projects/tor/ticket/23947) is done. ([diff](https://trac.torproject.org/projects/tor/wiki/doc/Snowflake?action=diff&version=34)) URL: https://trac.torproject.org/projects/tor/wiki/doc/Snowflake?version=34