[Filebeat] S3 input module should trim the delimiter of log line

[kwinstonix]

• Bug

For confirmed bugs, please report:

• Version: 7.8.0

Here log contains delimiter \n, so each event message filed also has \n.

I think It is better to trim \n, just like the behavior of reading log files

beats/x-pack/filebeat/input/s3/input.go

Lines 477 to 486 in d0f7058

	// handle s3 objects that are not json content-type
	offset := 0
	for {
	log, err := reader.ReadString('\n')
	if log == "" {
	break
	}
	if err == io.EOF {
	// create event for last line

[elasticmachine]

Pinging @elastic/integrations-platforms (Team:Platforms)

[exekias]

This looks reasonable to me, I think this is what we do for all the other inputs