Update path to real username and password

[jsf9k]

🗣 Description

I removed a redundant path in commit cisagov/guacamole-composition@16627d2 (from cisagov/guacamole-composition#21), but the redundant path is what was still being referenced by this role.

💭 Motivation and Context

This Ansible role errors out without this change, which is preventing me from building new COOL Guacamole AMIs containing the changes from cisagov/guacamole-composition#21.

🧪 Testing

All molecule tests and pre-commit hooks pass.

✅ Checklist

• [x] This PR has an informative and human-readable title.
• [x] Changes are limited to a single goal - eschew scope creep!
• [x] All relevant type-of-change labels have been added.
• [x] I have read the CONTRIBUTING document.
• [x] These code changes follow cisagov code standards.
• [x] All new and existing tests pass.