Example sometimes panics

[aleqdev]

What i did:

cargo run --example 02_authentication
    Finished dev [unoptimized + debuginfo] target(s) in 0.07s
     Running `target/debug/examples/02_authentication`
thread 'main' panicked at 'assertion failed: `(left == right)`
  left: `511`,
 right: `512`', examples/02_authentication.rs:11:5
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

02_authentication.rs:11:5:

    assert_eq!(handshake.B.num_bytes(), Srp6_4096::KEY_LEN);