logic change: Don't do anything if the slurper is not available.

[LeoChen98]

• What's change:
  • Add a new judgment let do nothing but retry when slurper out of service.
• Why?

  • Availability between slurper service and afv service are not sync. The situation, the slurper is down but everything else alive, is exist.

  • Slurper service and most of other VATSIM services are running on different servers, the connection availability between users and servers will be different too.

    For example, someone can connect to the network normally, but fail to connect to slurper. It will cause the trackaudio "kick" that man out of the afv service. It may cause the channel lose its controller unexpectedly, especially in the division with a leak World-Wire-Internet, such as VATPRC.

  • I think we should give the right of disconnecting back to the controllers when the slurper not available. Noticing the controllers they should disconnect by themselves during the slurper not available might be better than force to.

[KingfuChan]

3 possible solutions by @LeoChen98, @mic12130 and @KingfuChan:

1. Increase slurper request interval, timeout and retry times.
2. Additional request after 2 consecutive abnormal slurper data (with different data source, e.g. https://vatsim.dev/api/data-api/get-network-data/). Only disconnect when the additional source shows offline as well.
3. Alarm user and require in-time manual confirmation when 2 consecutive slurper data are abnormal. Disconnects when count-down ends.