Remove event fields from error log. (#37330)

Remove event fields from error log when the script processor
panics. This is an unlikely situation to happen as the Javascript
runtime we use should not panic on any error while executing
Javascript code, hence the event fields are just removed.

libbeat/processors/script/javascript/session.go

@@ -210,7 +210,6 @@ func (s *session) runProcessFunc(b *beat.Event) (out *beat.Event, err error) {
 		if r := recover(); r != nil {
 			s.log.Errorw("The javascript processor caused an unexpected panic "+
 				"while processing an event. Recovering, but please report this.",
-				"event", mapstr.M{"original": b.Fields.String()},
 				"panic", r,
 				zap.Stack("stack"))
 			if !s.evt.IsCancelled() {