title: Retrofit error java.io.IOException: Received authentication challenge is null
body: <p>I try to send on post a id application this work with HttpPost but when I try to do this with Retrofit I have the exception:</p>
  
  <pre><code>java.io.IOException: Received authentication challenge is null
  </code></pre>
  
  <p>Here is the method to post application id:</p>
  
  <pre><code>  @POST("/acces_token")
    @Headers({ "Content-type: application/json" })
    Response identifierApplication(@Header("X-FTVEN-ID") String header);
  </code></pre>
  
  <p>I searched on google but I didn't find this error with retrofit.</p>
  
  <p>Thank's for your response</p>