WString == Overload Changes in Arduino Master

[bwjohns4]

This may only be a short-lived issue, but here is a link to PR to fix an issue that was preventing WM to compile with the latest Arduino Master esp8266/Arduino#8569

The line would not compile and gave the error below:

if (_apPassword == NULL) _apPassword = "";

lib/WiFiManager/WiFiManager.cpp:4143:19: error: ambiguous overload for 'operator==' (operand types are 'String' and 'int')
4143 | if (_apPassword == NULL) _apPassword = "";

[tablatronix]

Thanks