Crash when log destination is unwritable

[djorlando24]

On MacOS, if the location in logger-config.json has no write permission or doesn't exist, the program fails ungracefully:

/Users/dduke/src/tplink-energy-monitor/src/services/data-logger.js:51
    console.warn('Error writing log for ' + device.alias + ' [' + device.deviceId + ']', err);
                                            ^

ReferenceError: device is not defined
    at writeLog (/Users/dduke/src/tplink-energy-monitor/src/services/data-logger.js:51:45)
    at /Users/dduke/src/tplink-energy-monitor/src/services/data-logger.js:60:7
    at FSReqCallback.oncomplete (node:fs:185:23)

A nice error saying "sorry your log file could not be written" would be better!