Set choice mode for navigation drawer

This should have enabled the current navigation drawer entry to be highlighted
by the call to setItemChecked() in selectItem(), but it still doesn't work.

src/net/i2p/android/router/activity/MainActivity.java

@@ -42,6 +42,7 @@ public class MainActivity extends ActionBarActivity {
 
         // Set a custom shadow that overlays the main content when the drawer opens
         mDrawerLayout.setDrawerShadow(R.drawable.drawer_shadow, GravityCompat.START);
+        mDrawerList.setChoiceMode(ListView.CHOICE_MODE_SINGLE);
         // Set the adapter for the list view
         mDrawerList.setAdapter(new ArrayAdapter<String>(this,
                 android.R.layout.simple_list_item_1, mFragmentTitles));