add permission www-data

[mohamednizar]

Purpose

The purpose of this PR is to fix #158

Checklist

• This PR doesn't commit any keys, passwords, tokens, usernames, or other secrets.
• I have read and understood the development best practices guidelines
• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation