Quartz DDL for Oracle DB execution ends with error message: ORA-00942 table or view does not exist

Description of problem:
Quartz DDL for Oracle (Supplementary tools) starts with delete and drop statements without checking existence of tables being deleted/dropped => this results in error message stated in the summary.

Version-Release number of selected component (if applicable):
BRMS/BPMS 6.0.0.ER3