fix README

README.md

@@ -14,7 +14,7 @@ A portable RSA implementation in pure Rust.
 ```rust
 use rsa::{Pkcs1v15Encrypt, RsaPrivateKey, RsaPublicKey};
 
-let mut rng = rand::thread_rng(); // [email protected].0
+let mut rng = rand::thread_rng(); // [email protected]
 let bits = 2048;
 let priv_key = RsaPrivateKey::new(&mut rng, bits).expect("failed to generate a key");
 let pub_key = RsaPublicKey::from(&priv_key);