prevents a panic during shutdown when there's no NATS connection

[autodidaddict]

Prevents the panic as described in #277

[autodidaddict]

New output when the node shuts down during startup:

[INF] 2024-07-01 10:48:43 - Loaded node configuration config_path=/home/kevin/nosandbox.json
[INF] 2024-07-01 10:48:43 - Telemetry status metrics=false traces=false
[ERR] 2024-07-01 10:48:43 - Failed to connect to NATS server err=nats: no servers available for connection
[INF] 2024-07-01 10:48:43 - Internal NATS server started client_url=nats://0.0.0.0:34307
[INF] 2024-07-01 10:48:43 - Host services configured services=[http kv messaging objectstore]
[WRN] 2024-07-01 10:48:43 - ⚠️  Sandboxing has been disabled! Workloads are spawned directly by agents
[WRN] 2024-07-01 10:48:43 - ⚠️  Do not run untrusted workloads in this mode!
[INF] 2024-07-01 10:48:43 - Workload manager stopping
[INF] 2024-07-01 10:48:43 - Spawning process manager stopping