Wifi provisioning manager

[karunt]

WIfi provisioning manager example in the latest release uses esp_event_handler_register to register event handler. But event loop api reference document mentions that this function is now obsolete and should be replaced with esp_event_handler_instance_register() instead. Any reason it's still being used in the example in the latest release or is it just oversight that it hasn't been updated yet in the example?

[mbratch]

Looks to me like the example just hasn't been updated. I use `esp_event_handler_instance_register` in my wifi provisioning code.