S3 file listing is not working if the prefix resolves to slash

[klopfdreh]

Type: Bug

Component:
S3

Describe the bug
If the prefix resolves to / the ListObjectsV2Request is not listing any files

Sample
Just put a txt file into an s3 bucket and use s3://mybucket/*.txt - the prefix resolves to / and the file is not listed

Solution
Use && !optionalPrefix.get().equals("/") to not set the prefix if it is only /

        ListObjectsV2Request.Builder listObjectsV2RequestBuilder = ListObjectsV2Request.builder().bucket(s3BucketName);
        if (optionalPrefix.isPresent() && !optionalPrefix.get().equals("/")) {
            listObjectsV2RequestBuilder = listObjectsV2RequestBuilder.prefix(optionalPrefix.get());
        }
        return listObjectsV2RequestBuilder;