fix bug in submitting firefox add-on.
Comments:
Your version was rejected because of the following problems:

1) Add-on contains duplicate/hidden/unused/unnecessary files or folders. These complicate the review process and may contain sensitive information about the system you created the XPI on. Please correct your packaging process so that these files aren't included.

Same content duplicated in the following directories:
resources/passwordrevealbutton/lib/
resources/passwordrevealbutton/data/