title: spring social twitter isConnected issue (RevokedAuthorizationException)
body: <p>I'm using Grails and the spring social twitter plugin. Everything works fine except in one case:</p>
  
  <p>I check if the user is connected to twitter via this piece of code</p>
  
  <pre><code>connectionRepository.findPrimaryConnection(Twitter.class)
  </code></pre>
  
  <p>while this works fine if I authorize the app in twitter, it still gives TRUE when I revoke the authorization. How can I make the function check if it's connected and if the user didn't revoke the authorization ? (right now it gives true, and I have a RevokedAuthorizationException  just after when trying to use the API).</p>
  
  <p><strong>UPDATE:</strong>
  I tried to catch the RevokedAuthorizationException in order to redirect the user to twitter, it works BUT now I have a weird behavior: if a user revoke once the authorization, even if he then authorizes the app, it keeps giving a RevokedAuthorizationException ?!</p>
  
  <p>Thank you.</p>