HPCC-8891 ECLPlayground broken

General regression broke ECL Playground (and possibly other widgets).

Signed-off-by: Gordon Smith <gordon.smith@lexisnexis.com>
Merge pull request #4033 from GordonSmith/HPCC-8891

HPCC-8891 ECLPlayground broken

Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>