Error in directory list fetch

On Windows directory listing  API fails due to unsupported char colon : in the temporary file name.
Removed colon character from timestamp

Author: sunilnatraj

src/main/java/org/openrefine/extensions/files/importer/FilesImportingController.java

@@ -82,7 +82,7 @@ public void doPost(HttpServletRequest request, HttpServletResponse response)
 
     private void getDirectoryHierarchy(HttpServletRequest request, HttpServletResponse response, Properties parameters) throws ServletException, IOException {
         String dirPath = parameters.getProperty("dirPath");
-        String fileName = "directoryList_OR_".concat(Instant.now().toString());
+        String fileName = "directoryList_OR_".concat(Instant.now().toString().replace(":", ""));
         Path outputFile = Files.createTempFile(fileName, ".json");
         FilesImporter.generateDirectoryTree(dirPath, outputFile);
         respondJSON(response, Files.readString(outputFile));