Fall Back to Closest Server

Added

• Added an optional Fall Back to Closest Server setting.
• When enabled, the integration still tries the configured Speedtest server first on every run.
• If Ookla reports that the configured server is unavailable, the integration retries once using the closest
  available server.

Fixed

• Prevents tests from failing with NoServersException when a specified server temporarily drops off Ookla’s
  server list.