Username can be 16 * 3 bytes (#789)

https://github.com/PaperMC/Velocity/pull/936

BungeeCord-Patches/0056-Additional-DoS-mitigations.patch

@@ -180,7 +180,7 @@ index 5186a6a8..3224b0d2 100644
 +        // Accommodate the rare (but likely malicious) use of UTF-8 usernames, since it is technically
 +        // legal on the protocol level.
 +        if (protocolVersion >= ProtocolConstants.MINECRAFT_1_19) return -1;
-+        return 1 + (16 * 4);
++        return 1 + (16 * 3);
 +    }
 +    // Waterfall end
  }