NFD

Right now, logging section in config file is shared between nfd and nrd. LoggerFactory::onConfig throws when unknown section is encountered.

This makes impossible to set NRD-specific logging and not to fail NFD, and impossible to set NFD-specific logging and not to fail NRD.

My proposal is not to fail when unknown logger section is encountered and simply ignore that (may be log in TRACE, but not in WARN)