Fix 2215274 - Duplicate widgets appearing on top of each other

My fix for duplicate icons didn't account for widgets.

src/com/android/launcher2/LauncherModel.java

@@ -607,6 +607,7 @@ public class LauncherModel extends BroadcastReceiver {
                 */
 
                 mItems.clear();
+                mAppWidgets.clear();
 
                 final Cursor c = contentResolver.query(
                         LauncherSettings.Favorites.CONTENT_URI, null, null, null, null);