[Bug] Auth.current_user hangs when connected to WiFi but don't have internet

### [REQUIRED] Please fill in the following fields:

* Pre-built SDK from the [website](https://firebase.google.com/download/cpp) or open-source from this repo: open-source
* Firebase C++ SDK version: latest?
* Problematic Firebase Component: Auth
* Other Firebase Components in use: Firestore
* Platform you are using the C++ SDK on: Windows
* Platform you are targeting: desktop

### [REQUIRED] Please describe the issue here:

If you're connected to a WiFi that doesn't have internet, like at the airport or coffee shop (Starbucks is one), the `Auth.current_user` call hangs indefinitely.

#### Steps to reproduce:

Have you been able to reproduce this issue with just the [Firebase C++ quickstarts](https://github.com/firebase/quickstart-cpp) ? I didn't try before i left the repro environment

What's the issue repro rate? 100%

What happened? How can we make the problem occur?
This could be a description, log/console output, etc.

If you set Arc as your default browser and try to connect to a WiFi that doesn't have internet, it will hang until connected to internet.

This issue doesn't reproduce simply when not connected to internet. Which is very problematic for a browser where folks need to authenticate to the WiFi before they can get internet.

If you have a downloadable sample project that reproduces the bug you're reporting, you will
likely receive a faster response on your issue.

https://releases.arc.net/windows/ArcInstaller.exe

#### Relevant Code:

`auto user = Auth.current_user()`