HPCC-11237 Return correct GraphNum in WsWorkunits/WUGraphTiming

A bug is fixed for returning GraphNum in WsWorkunits/WUGraphTiming.

Signed-off-by: Kevin Wang kevin.wang@lexisnexis.com
Merge pull request #5708 from wangkx/h11237

HPCC-11237 Return correct GraphNum in WsWorkunits/WUGraphTiming

Reviewed-By: Gordon Smith <gordon.smith@lexisnexis.com>
Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>