Remove `shutdown()` hack, which does not work any more with dynamic API keys.

src/main/java/com/nutomic/syncthingandroid/syncthing/SyncthingService.java

@@ -245,11 +245,6 @@ public class SyncthingService extends Service {
             });
             registerOnWebGuiAvailableListener(mApi);
             Log.i(TAG, "Web GUI will be available at " + mConfig.getWebGuiUrl());
-
-            // HACK: Make sure there is no syncthing binary left running from an improper
-            // shutdown (eg Play Store update).
-            // NOTE: This will log an exception if syncthing is not actually running.
-            mApi.shutdown();
             updateState();
         }
     }