This adds the ability to specify if the MQTT broker connection is secure via a checkbox on the config page of WiFiManager.
Also added to the WiFiManager config page is a text box to enter the brokers TLS certificate.
In the case of using manual configuration a new macro is created MQTT_SECURE_DEFAULT.
When defined as true a secure connection will be requested and the certificate defined in user_config.h will be used.
DigiH