Fix order of the directory separator when download an image

Ensure the internal repository path is applied after the fileset
separator so that the internal structure is preserved and the data
can be read by Bio-Formats

src/main/java/omero/gateway/facility/TransferFacilityHelper.java

@@ -135,7 +135,7 @@ List<File> downloadImage(SecurityContext context, String targetPath,
                 for (FilesetEntry fse: fs.copyUsedFiles()) {
                     OriginalFile of = fse.getOriginalFile();
                     String ofDir = of.getPath().getValue().replace(repoPath, "");
-                    File outDir = new File(targetPath+File.separator+ofDir+File.separator+fs_dir);
+                    File outDir = new File(targetPath+File.separator+fs_dir+File.separator+ofDir);
                     outDir.mkdirs();
                     File saved = saveOriginalFile(context, of, outDir);
                     if (saved != null)