This bug produces a nasty deadlock in CAF if:

• the default log level is > quiet
• the user configures logger.file-verbosity = 'quiet'
• the user sets logger.console = 'none' (default)

Now, the logger will not spin up its thread (neither terminal nor file output), but logger::accept happily returns true. Eventually, the ring buffer for the logger is full and the application comes to a grinding halt because no one ever reads from the queue.