update from ver 4 to 5

I have made small project of an MQTT client using ESP8266 d1 mini.
My esp8266 hangs every time I use the compiled code with PersWiFiManager ver 5 but it works fine with 4. 
You can see my source code at: https://github.com/HA4ever37/D1Mini_OLED_MQTT/blob/master/D1Mini_OLED_MQTT.ino

Thanks