Log a lot more about subroutings

mobile/src/main/java/be/mygod/vpnhotspot/net/Subrouting.kt

@@ -62,6 +62,7 @@ class Subrouting(private val parent: Routing, priority: Int, val upstream: Strin
 
     init {
         Timber.d("Subrouting initialized from %s to %s", parent.downstream, upstream)
+        Timber.d(Thread.currentThread().stackTrace.joinToString("\n"))
         IpNeighbourMonitor.registerCallback(this)
     }
 
@@ -71,6 +72,7 @@ class Subrouting(private val parent: Routing, priority: Int, val upstream: Strin
     override fun close() {
         IpNeighbourMonitor.unregisterCallback(this)
         Timber.d("Subrouting closed from %s to %s", parent.downstream, upstream)
+        Timber.d(Thread.currentThread().stackTrace.joinToString("\n"))
     }
 
     override fun onIpNeighbourAvailable(neighbours: List<IpNeighbour>) = synchronized(parent) {

mobile/src/main/java/be/mygod/vpnhotspot/net/monitor/UpstreamMonitor.kt

@@ -77,8 +77,7 @@ abstract class UpstreamMonitor {
 
     fun registerCallback(callback: Callback) {
         synchronized(this) {
-            if (!callbacks.add(callback)) return
-            registerCallbackLocked(callback)
+            if (callbacks.add(callback)) registerCallbackLocked(callback)
         }
     }
     fun unregisterCallback(callback: Callback) = synchronized(this) {