osmo-hlr: Force log stderr blocking-io in --db-check mode
When --db-check is used, osmo-hlr actually becomes a synchronous non-interactive program instead of a daemon. In that case, we want to use blocking-io since it doesn't use the event loop, so we want to flush all logging synchronously before exiting.
Usually the user will pass the same osmo-hlr.cfg when running with --db-check, which means most probably won't be using blocking-io (as expected when osmo-hlr runs in daemon mode). Since --db-check converts osmo-hlr to a cmdline which exits after checks are done, we actually want to force blocking-io in that case, so that all content is written to stderr before finishing the process.
When --db-check is used, osmo-hlr actually becomes a synchronous non-interactive program instead of a daemon. In that case, we want to use blocking-io since it doesn't use the event loop, so we want to flush all logging synchrnously before exiting.
