fixed obscure bug, when firmware isn't compiled with FS support (filesystem size = 0kb), an error is thrown when initializing LittleFS, and the application returned with Config in an unknown uninitialized
state, and as soon as MDNS refresh happened, it would crash attempting to copy unknown memory area when initializing MDNS zones, leaving the unit in an endless crash loop. Now throws an error in the log,
while on debug, maybe it should be more explicit !!