HPCC-10276 Fix regression in 5.0 WsEcl jsonp support

Signed-off-by: Anthony Fishbeck <anthony.fishbeck@lexisnexis.com>
Merge pull request #5798 from afishbeck/wseclJsonpBroken

HPCC-10276 Fix regression in 5.0 WsEcl jsonp support

Reviewed-By: Gordon Smith <gordon.smith@lexisnexis.com>
Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>