serve s3: fix list objects encoding-type

Before this change rclone would always use encoding-type url even if
the client hadn't asked for it.

This confused some clients.

This fixes the problem by leaving the URL encoding to the gofakes3
library which has also been fixed.

Fixes #7836

cmd/serve/s3/backend.go

@@ -52,7 +52,7 @@ func (b *s3Backend) ListBuckets(ctx context.Context) ([]gofakes3.BucketInfo, err
 	for _, entry := range dirEntries {
 		if entry.IsDir() {
 			response = append(response, gofakes3.BucketInfo{
-				Name:         gofakes3.URLEncode(entry.Name()),
+				Name:         entry.Name(),
 				CreationDate: gofakes3.NewContentTime(entry.ModTime()),
 			})
 		}
@@ -227,7 +227,7 @@ func (b *s3Backend) GetObject(ctx context.Context, bucketName, objectName string
 	}
 
 	return &gofakes3.Object{
-		Name:     gofakes3.URLEncode(objectName),
+		Name:     objectName,
 		Hash:     hash,
 		Metadata: meta,
 		Size:     size,