Radio Config: always try to start telemetry on cancel

- Calling the startTelemetryMode when cancling radio
  config restarts the device by tearing down EAAccessory
  connection and keeps the device in a better state so that
  subsequent attempts at radio configureation have a better
  chance of working properly.
Merge pull request #103 from fightingwalrus/igcs-183-radio-config-improvements

Radio Config: always try to start telemetry on cancel