[TECH. SUPPORT] LPS-32983

Hi Tamás,

These commits fix file upload to DDL records.

* Commit 15d4e5df4ceb3b76e347d62288c6413fc238a2e6 introduced such changes to init.ftl which prevented method uploadFieldFile in DDMImpl from extracting the InputStream from the given uploadRequest.
* Method getFieldNames returns only a single value for each file-upload fields, thus the loop within method uploadFieldFile is unnecessary.
* While testing the solution, I discovered that NPE is thrown when I try to download a previously uploaded file.

Cheers,
Laci.