message: Better error message ( )
diff: @@ -26,8 +26,11 @@ class RegistrationController extends Controller {
  }
  try {
  - await userService.findByIdentity('mailto:' + ctx.request.body.emailAddress);
  - throw new Error('User already exists');
  + if (await userService.findByIdentity('mailto:' + ctx.request.body.emailAddress)) {
  + ctx.status = 303;
  + ctx.response.headers.set('Location', '/register?msg=User+already+exists.+Please+use+a+different+email');
  + return;
  + }
  } catch (err) {
  if (!(err instanceof NotFound)) {
  throw err;
  