Fix non-UI thread call

src/com/annimon/donetskwebcam/WebcamViewerFragment.java

@@ -78,8 +78,14 @@ public class WebcamViewerFragment extends Fragment {
 	}
 	
 	public void update() {
+	    contentImage.post(new Runnable() {
+            
+            @Override
+            public void run() {
                 contentImage.setImageDrawable(imageUrl);
             }
+        });
+	}
 	
 	private void autoUpdate() {
         TimerTask task = new TimerTask() {