Fix typo in class name

Author: Dave Syer

logout/README.adoc

@@ -106,7 +106,7 @@ private Filter csrfHeaderFilter() {
  return new OncePerRequestFilter() {
  @Override
  protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response,
- FilterChain filterChain) throws ServletException, IOExeption {
+ FilterChain filterChain) throws ServletException, IOException {
  CsrfToken csrf = (CsrfToken) request.getAttribute(CsrfToken.class.getName());
  if (csrf != null) {
  Cookie cookie = WebUtils.getCookie(request, "XSRF-TOKEN");