Ensure receiver unregistered synchronously in onDestroy

mobile/src/main/java/be/mygod/vpnhotspot/util/Utils.kt

@@ -19,6 +19,7 @@ import androidx.databinding.BindingAdapter
 import be.mygod.vpnhotspot.App.Companion.app
 import be.mygod.vpnhotspot.room.macToString
 import be.mygod.vpnhotspot.widget.SmartSnackbar
+import java.lang.IllegalArgumentException
 import java.net.InetAddress
 import java.net.NetworkInterface
 import java.net.SocketException
@@ -35,6 +36,12 @@ fun Long.toPluralInt(): Int {
     return (this % 1000000000).toInt() + 1000000000
 }
 
+fun Context.ensureReceiverUnregistered(receiver: BroadcastReceiver) {
+    try {
+        unregisterReceiver(receiver)
+    } catch (_: IllegalArgumentException) { }
+}
+
 @SuppressLint("Recycle")
 fun <T> useParcel(block: (Parcel) -> T) = Parcel.obtain().run {
     try {