HPCC-9637 - Uninitialized ENTH counter

The ENTH 'counter' could be left uninitialized by
setInitialCounter, if the numerator was 0
Only side-effect was spurious tracing.

Signed-off-by: Jake Smith <jake.smith@lexisnexis.com>
Merge pull request #4610 from jakesmith/hpcc-9637

HPCC-9637 - Uninitialized ENTH counter

Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>