Fix broken startup sync-lock

## Issue
In 38c13cf5, an additional `doGetAndPopulatePreferences` was added in `doSignIn` to ensure we have populated the preferences at least once. With that, `doHandleSyncComplete` can skip `doGetAndPopulatePreferences` is there is no change in the hash.

The addition broke the "initial sync lock", thus incorrectly allowing users to change preferences when the process is not completed.

## Change
I think the additional call is no longer needed since we now store a local hash for comparison, so `doGetAndPopulatePreferences` wouldn't be incorrectly skipped in the first ever `doHandleSyncComplete`.

ui/redux/actions/app.js

@@ -531,7 +531,6 @@ export function doSignIn() {
       pushNotifications.validate(user.id);
     }
 
-    dispatch(doGetAndPopulatePreferences());
     dispatch(doNotificationSocketConnect(true));
     dispatch(doNotificationList(null, false));
     dispatch(doCheckPendingClaims());