title: i successfully log in but can only access the site after 2nd try
body: <p>I copied this guy's tutorial exactly and got it running in IntelliJ and Spring 2.1.7:
  <a href="https://medium.com/@gustavo.ponce.ch/spring-boot-spring-mvc-spring-security-mysql-a5d8545d837d" rel="nofollow noreferrer">https://medium.com/@gustavo.ponce.ch/spring-boot-spring-mvc-spring-security-mysql-a5d8545d837d</a></p>
  
  <p>I think I had to make the html file "/admin/home.html" myself because he didn't have that for some reason.</p>
  
  <p>When I first successfully log in I'm immediately redirected to:
  <a href="http://localhost:8080/error" rel="nofollow noreferrer">http://localhost:8080/error</a></p>
  
  <p>But then i can manually go to /admin/home or if I log in again I'm automatically redirected there.  In SecurityConfiguration.java I believe this line says I should get redirected there:
  .defaultSuccessUrl("/admin/home")</p>
  
  <p>But for some reason the the first time I log in I'm redirected to the error page.  Anybody know why?</p>