MQTT sync after reboot

[SuperNinja]

@shramik_salgaonkar
Some test have made but fell a little to oblivion
@rsiegel: ESP8266 : using syncAll() function - #4 by rsiegel
And :

@rsiegel

Ultimately I found out the retain flag was not set – its a matter of changing it in our development environment and doing some QA on our side. Thus far there has not been any action on it – I’ll make a renewed request and see if we can prioritize it on our end.