icinga2: Reset Event#ID before resending ack set event

internal/icinga2/client_api.go

@@ -322,6 +322,7 @@ func (client *Client) checkMissedChanges(ctx context.Context, objType string, ca
 		case catchupEventCh <- &catchupEventMsg{eventMsg: &eventMsg{ev, attrs.LastStateChange.Time()}}:
 			stateChangeEvents++
 			if fakeEv.Type == event.TypeAcknowledgementSet {
+				fakeEv.ID = 0 // We don't want to reference a previously sent event, so reset its ID!
 				select {
 				// Retry the AckSet event so that the author of the ack is set as the incident
 				// manager if there was no existing incident before the above state change event.