notify: truncate description for PagerDuty v1 (#1922)
notify: truncate description for PagerDuty v1 (#1922)

Signed-off-by: Simon Pasquier <38e2d22e48be18381a59028f88390cad04670376@redhat.com>
GoogleCloudPlatform/alertmanager,prometheus/alertmanager,GoogleCloudPlatform/alertmanager,GoogleCloudPlatform/alertmanager,prometheus/alertmanager,GoogleCloudPlatform/alertmanager,prometheus/alertmanager,prometheus/alertmanager