HPCC-10667 New ECL Watch Deselection broken

"clearSelection" parameter name misspelled in previous release.

Signed-off-by: Gordon Smith <gordon.smith@lexisnexis.com>
Merge pull request #5397 from GordonSmith/HPCC-10667

HPCC-10667 New ECL Watch Deselection broken

Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>