Returning 500 instead of 503 when cloud is unavailable

[netoax]

The back-end is returning 500 (Internal server error) instead of 503 (Service unavailable) when connection with cloud service times out. The fix should be to include ETIMEDOUT and EAGAIN to the list of request errors, which means the cloud service is unavailable.

Steps to reproduce

1. Bring WebUI's container up
2. Bring Cloud's container up
3. Don't connect them together
4. Run cloud configuration
5. Try to sign up

Expected result
Show an error message telling that the cloud service is unavailable.

Actual result
Shows an error message telling that an unexpected error occurred.