android.bluetooth.BluetoothSocket.isConnected() is only 14+
java.lang.NoSuchMethodError: android.bluetooth.BluetoothSocket.isConnected
at org.fdroid.fdroid.net.bluetooth.BluetoothConnection.open(BluetoothConnection.java:37)
at org.fdroid.fdroid.net.bluetooth.BluetoothClient.openConnection(BluetoothClient.java:31)
at org.fdroid.fdroid.net.BluetoothDownloader.<init>(BluetoothDownloader.java:30)
at org.fdroid.fdroid.net.DownloaderFactory.create(DownloaderFactory.java:56)
at org.fdroid.fdroid.RepoUpdater.downloadIndex(RepoUpdater.java:97)
at org.fdroid.fdroid.RepoUpdater.update(RepoUpdater.java:131)
at org.fdroid.fdroid.UpdateService.onHandleIntent(UpdateService.java:377)
at android.app.IntentService$ServiceHandler.handleMessage(IntentService.java:59)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:130)
at android.os.HandlerThread.run(HandlerThread.java:60)