message: fix sip002 wiki url
diff: @@ -45,6 +45,6 @@ validate_type!(validate_usize, usize, "should be unsigned integer");
  pub fn validate_server_url(v: String) -> Result<(), String> {
  match ServerConfig::from_url(&v) {
  Ok(..) => Ok(()),
  - Err(..) => Err("should be SIP002 (https://shadowsocks.org/en/spec/SIP002-URI-Scheme.html) format".to_owned()),
  + Err(..) => Err("should be SIP002 (https://shadowsocks.org/en/wiki/SIP002-URI-Scheme.html) format".to_owned()),
  }
  }
  