Bssid = null since update to Catalina 10.15.4

[HelgeKeck]

The used code from the example:

HelloCoreWlanSample.cs

doesnt work anymore as expected. Dont know if it is a bug or a new restriction, but the system always returns NULL for the Bssid value.

[Chris Hamons]

This appears to be an Apple change: https://forums.developer.apple.com/thread/124189

I'm going to leave it open, as if there are ways to fix the sample I'm all ears.

[Michael John Peña]

You need to request for location access for it to work.

using CoreLocation;

        var manager = new CLLocationManager();
        manager.RequestAlwaysAuthorization();

[HelgeKeck]

👍

[Michael John Peña]

Created a PR:

#139