Skip auth-sync reload if already authenticating

## Issue
Closes #3009: "Tabs reloading itself when multiple are opened simultaneously"

ui/redux/middleware/auth-token.js

@@ -11,7 +11,7 @@ type Store = { dispatch: Dispatch, getState: GetState };
 export const populateAuthTokenHeader = (store: Store) => {
   return (next: any) => (action: any) => {
     // @if TARGET='web'
-    const { dispatch } = store;
+    const { dispatch, getState } = store;
 
     switch (action.type) {
       case ACTIONS.USER_FETCH_SUCCESS:
@@ -28,8 +28,9 @@ export const populateAuthTokenHeader = (store: Store) => {
         const isVerifyPage = location.href.includes(PAGES.AUTH_VERIFY) && !location.href.includes(PAGES.REWARDS_VERIFY);
         const isNewAccount = LocalStorage.getItem(LS.IS_NEW_ACCOUNT) === 'true';
         const xAuth = (Lbry.getApiRequestHeaders() || {})[X_LBRY_AUTH_TOKEN] || '';
+        const state = getState();
 
-        if (!xAuth) {
+        if (!xAuth && !state.user.authenticationIsPending) {
           if (isVerifyPage) {
             if (isNewAccount) {
               LocalStorage.removeItem(LS.IS_NEW_ACCOUNT);