letsencrypt-crontab state fails when cron module is absent and can't be loaded

[aboe76]

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          ID: letsencrypt-crontab-example.com
    Function: cron.absent
        Name: /usr/bin/certbot renew example.com
      Result: False
     Comment: State 'cron.absent' was not found in SLS 'letsencrypt.domains'
              Reason: 'cron' __virtual__ returned False: cron module could not be loaded
     Changes:   

This state should be encapsulated with a test to see if cron module is loaded or cron is available...