TCPS-709 — Log level decremented in response to a received signal
The log level (maximum severity code which will be logged) can be set between I (6, LOG_INFO) to F (9, FULL_DEBUG). When the proxy receives signal SIGUSR1, the log level is decremented by one, i.e., only more severe messages will be logged. Signalling the parent process changes the log level also in all child processes.