Remove "logging in" screen

I understand what it does, but I don't think it's necessary or desirable to block the entire UI while the user waits for this. A little "connecting" or "updating balance" indicator in the UI would suffice. "No connection" when there's no internet or Tor is blocked. Having to wait >10 seconds to open an app is annoying. Getting stuck on "logging in" without network even more so. The BTC balance and fiat conversion can be cached locally (just add an indicator that it's not up-to-date / updating).