`FileInputStream` leak when using `filesystem` provider and performing a multipart upload

I'm using gaul/s3proxy built on the latest jclouds. The provider configuration is "filesystem", and basedir configuration is a directory where a NFS is mounted.

When I performed a multipart upload, I found that files such as ".nfs00000000100000bf00000005" remained in the directory after uploading. Each file corresponded to one part and the files could not be deleted. The error "Device Busy" was reported. These files will disappear automatically after restarting s3proxy.

I found this PR, and tried to restore following snippet and it worked. But this is just a temporary fix.

         InputStream is = blob.getPayload().openStream();
         if (is instanceof FileInputStream) {
            // except for FileInputStream since large MPU can open too many fds
            is.close();
            payload = blob.getPayload();
         } else {
            blob.resetPayload(/*release=*/ false);
            payload = new InputStreamPayload(is);
         }