Config.json file is ignored if additional settings are not defined

[2delarosa]

To bypass the GUI config mode, one must define loglevel, logserial, and flushlog in the settings section of the config.json for it to be valid. See log output below for loglevel

12:42:52.553 > 68 [DEBUG]: void setup(): Before Homie setup())
12:42:52.608 > ✖ Config file is not valid, reason: loglevel setting is missing
12:42:52.614 > Configuration invalid. Using CONFIG MODE
12:42:52.692 > 💡 Firmware pool-controller (2.0.0)
12:42:52.692 > 🔌 Booting into config mode 🔌