timer should run on ui thread to prevent crash

src/de/tudarmstadt/informatik/hostage/sync/wifi_direct/ui/WiFiP2pSyncActivity.java

@@ -122,7 +122,12 @@ public class WiFiP2pSyncActivity extends Activity implements AdapterView.OnItemC
 		new Timer().scheduleAtFixedRate(new TimerTask() {
 			@Override
 			public void run() {
-				searchForDevices();
+				runOnUiThread(new Runnable() {
+					@Override
+					public void run() {
+						searchForDevices();
+					}
+				});
 			}
 		}, 1000, 5000); // search for devices every 5 seconds
     }