Update Cloud ICE server fetch update and reset logic

[klejejs]

There were some issues with the current logic, so it is updated in the following ways:

• If the cloud subscription has expired, there is no point in fetching new servers, and they should be set to an empty list.
• If, for some reason, the fetching does happen and 401 or 403 is returned, we should reset the ICE servers to an empty list instead of leaving them there and having the code reattempt fetching them based on the existing timestamps.
• The listener should be called even on request error as the servers might now change also in those cases.
• The listener should be called even on an empty ICE servers list as we don't need old servers with credentials to be left for HA to use.