Fails when running with `jetp check-ssh`.

Example:

```console
$ jetp check-ssh -i inventory -p playbooks/prometheus.yml --tags blackbox_exporter -r roles
----------------------------------------------------------
> playbook start: redacted/jetp/playbooks/prometheus.yml
----------------------------------------------------------
> play: Install blackbox exporter
----------------------------------------------------------
> batch 1/1, 1 hosts
----------------------------------------------------------
> (blackbox_exporter) begin task: directory
… redacted.example.com => running
✓ redacted.example.com => matched
----------------------------------------------------------
> (blackbox_exporter) begin task: Check if file is downloaded or extracted
… redacted.example.com => running
✓ redacted.example.com => would run
----------------------------------------------------------
> (blackbox_exporter) begin task: Download blackbox_exporter
… redacted.example.com => running
! error: redacted.example.com: failed to parse conditional: (ne file_stat.rc 0): one or more parameters may be undefined
----------------------------------------------------------
> play failed: Install blackbox exporter
no hosts remaining
```