qt4: enable dragging from everywhere

This enables drag items from service discovery, I don't see why user
shouldn't be allowed to drag his/her favorite shoutcast/other item to
medialibrary or playlist from service-discovery lists.

modules/gui/qt4/components/playlist/playlist_model.cpp

@@ -168,8 +168,8 @@ Qt::ItemFlags PLModel::flags( const QModelIndex &index ) const
 
         PL_UNLOCK;
 
-        flags |= Qt::ItemIsDragEnabled;
     }
+    flags |= Qt::ItemIsDragEnabled;
 
     return flags;
 }