message: Fixes a bug where the browser is given a link with two // causing it to redirect. This is because the base url has a trailing slash and the redirect path has a beginning slash. The fix strips the beginning slash if both have their respective slashes.
diff: if (!error) {
  var next = localStorage.getItem('next') || '';
  if (next) {
  + if (next[0] === '/' && json.loginSuccessURL.substr(-1) === '/') {
  + while (next[0] === '/') {
  + next = next.substr(1); //remove any slash in front of "next"
  + }
  + }
  localStorage.removeItem('next');
  window.location = json.loginSuccessURL + next;
  } else {
  