Bump version of Snowflake in Tor Browser to 221f1c41
In addition to some code refactors and cleanups, we've added some new features and fixes to the Snowflake client since the last version shipped in Tor Browser:
- Moved client messages to the broker into the HTTP body
- Fixed some race condition bugs
- AMP cache rendezvous
- Added the ability to specify Snowflake command-line arguments through SOCKS so they can be used as Bridge lines
- Some performance tuning for KCP/smux
In particular, the AMP cache feature might be useful in near future blocking attempts of Snowflake.