If the nagios disk is read-only, pagerduty script just dies on enqueue

[afreiberger]

If the host running nagios ends up with the pagerduty_queue directory in a read-only state, the "enqueue" action just dies upon failure to open and write the alert details into the queue.

I would suggest that it should have a fallback routine of trying to directly send an alert to the pagerduty API that the queue is not writable before dying on line 247.