Fix the issue that the log does not stop when config=-1.

[hongran]

I added an if structure in the worker loop and it checks the config. If config=-1, continue the loop without creating a log.
This fix is tested.

[anjohnson]

This is a fix for #31, but it doesn't short-circuit or de-register the trap-write routine, so the performance of records whose puts are configured to be logged won't change by much if the config is changed at runtime. The field values before and after each put are still queued and sent to the lower-priority logger thread, it just discards them.

Re-running the vs2019/static test which looks like it failed due to GitHub CI infrastructure reasons.