Fix frontend mishandling of null userinfo (#1795)

* Fix frontend mishandling of null userinfo

If the authentication is disabled, the userinfo endpoint returns null.
This case needs to be handled.

 #1780

* Small fix for handling refesh tokens in auth

client/src/actions/index.js

@@ -43,7 +43,7 @@ async function configFetch(dispatch) {
 
 async function userInfoFetch(dispatch) {
   return fetchJson("userinfo").then((response) => {
-    const userinfo = { ...response.userinfo };
+    const { userinfo } = response || {};
     dispatch({
       type: "userinfo load complete",
       userinfo,