Set esp32 to connect AP to sta mode, but esp32 drops.
log：
connect wifi succeed
[D][WiFiGeneric.cpp:293] _eventCallback(): Event: 5 - STA_DISCONNECTED
[W][WiFiGeneric.cpp:298] _eventCallback(): Reason: 2 - AUTH_EXPIRE
[2018:06:28:17:18:22]IP address: 0.0.0.0
What is AUTH_EXPIRE