title: Gatling in scala how to get url from redirect
body: <p>I using gatling ver 2.3.0 in scala. Is it possible after send request get a url from redirect to variable? e.g. I request for 192.168.1.30:8080/ and this link redirect me to 192.168.1.30:8080/token/123, can I get /token/123? I tried with this code but occurs error header.find.exists, found nothing but in Fiddler I see this header </p>
  
  <pre><code> val httpConf = http
          .baseURL("http://192.168.1.30:8080")
   .acceptHeader("text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8")
              .acceptEncodingHeader("gzip, deflate")
              .acceptLanguageHeader("en-US,en;q=0.5")
              .userAgentHeader("Mozilla/5.0 (Macintosh; Intel Mac OS X 10.8; rv:16.0) Gecko/20100101 Firefox/16.0")
  
  val scn = scenario("SCENARIO2")
  .exec(http("open")
    .get("/")
    .check(header("Location").saveAs("url")))
  .exec(session =&gt; {
    val urlN = session.get("url").asOption[String]
    print(urlN.getOrElse("nothing"))
    session
  })
  </code></pre>