fix(SparkUtils): Remove conflicting content encoding header data.

Author: binh-dam-ibigroup

src/main/java/com/conveyal/datatools/common/utils/SparkUtils.java

@@ -53,9 +53,9 @@ public static HttpServletResponse downloadFile(File file, String filename, Reque
         if (file == null) logMessageAndHalt(req, 404, "File is null");
         HttpServletResponse raw = res.raw();
         raw.setContentType("application/octet-stream");
-        raw.setHeader("Content-Disposition", "attachment; filename=" + filename);
         // Override the gzip content encoding applied to standard API responses.
-        res.header("Content-Encoding", "identity");
+        raw.setHeader("Content-Encoding", "identity");
+        raw.setHeader("Content-Disposition", "attachment; filename=" + filename);
         try (
             FileInputStream fileInputStream = new FileInputStream(file);
             ServletOutputStream outputStream = raw.getOutputStream()