Restore stdout/stderr when restoring loggers (logging tests sometimes redirect them).
Restore stdout/stderr when restoring loggers (logging tests sometimes redirect them).


Former-commit-id: 735b39ba17c9ce78923fba2a83b048f96ce7c581
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine