HPCC-10794 - Sasha search fails to find some workunits

If a workunit search has a pattern which includes a time, Sasha
incorrectly normalizes the date/time format of the workunit,
introducing a spurious '-' and in so doing, fails to find the
workunits being searched for.

Signed-off-by: Jake Smith <jake.smith@lexisnexis.com>