[Android]'WARNING: app.launch.local_path is deprecated for Crosswalk' sh...

...ould not be showed twice

BUG=https://crosswalk-project.org/jira/browse/XWALK-2118
This is a C-ism. Just set `manifest = None` in the `if` clause below, you don't need to declare this variable in the outer scope, and you really should not use 0 here. `None` exists for a reason.