Remove stuff

We don't actually need to null check `getScanResults()`'s return value. I confirmed that it never returns null and it returns a new copy we can freely modify. `getScanResults()` returns a zero-length `ArrayList` when there are no scan results.

https://github.com/android/platform_frameworks_base/blob/6f2b31fcf57e4e7f5cd8af9b66619c8f5825a850/wifi/java/android/net/wifi/WifiStateMachine.java#L887

This PR also removes the "token" JSON property to fix #48.