str -> bool

src/client/js/nologin.jsx

@@ -27,7 +27,7 @@ if (installerFormElem) {
 // render loginForm
 const loginFormElem = document.getElementById('login-form');
 if (loginFormElem) {
-  const isRegistering = loginFormElem.dataset.isRegistering;
+  const isRegistering = loginFormElem.dataset.isRegistering === 'true';
   const csrf = loginFormElem.dataset.csrf;
   ReactDOM.render(
     <I18nextProvider i18n={i18n}>