title: Sonar Methods should not be empty at the constructor
body: <p>I updated my Sonar to Version 5.1.2, and the issue <code>Methods should not be empty</code> appears on this code:</p>
  
  <pre><code>public User() {}
  
  public User (String login) {
     this.login = login;
  }
  </code></pre>
  
  <p>It seems to be a bug. Am I right? Because this didn't happen before.</p>