title: GitLab: deleted a user and recreating same user give error "Username has already been taken Username already exists"
body: <p>I'm using GitLab Community Edition 8.2.2</p>
  
  <p>What's the correct way to delete a user if you want to recreate it?  </p>
  
  <p>In my case the user wanted to swap the  userid and name fields but keep his email address unchanged.  When I try to add the user, after already deleting him.<br>
  I get the error: </p>
  
  <blockquote>
    <p>"Username has already been taken Username already exists" even though
    the user does not exists.</p>
  </blockquote>