Fixed postgresql_db failing on Python 2.4 with --check
Fixed postgresql_db failing on Python 2.4 with --check

This reverts commit 81cbdb6c8cf54c41ba2ee3330c968e2feea05a5c and adds ignoring of the SystemExit exception because of Python 2.4.
Merge pull request #281 from kustodian/postgresql_db_fix_for_python_24_checkmode

Fixed postgresql_db failing on Python 2.4 with --check