HPCC-11771 Allow downloading of ECL

Fixes HPCC-11771

Signed-off-by: Gordon Smith <gordon.smith@lexisnexis.com>
Merge pull request #6144 from GordonSmith/HPCC-11771

HPCC-11771 Allow downloading of ECL

Reviewed-By: Miguel Vazquez <miguel.vazquez@lexisnexis.com>
Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>