Fix: Wireguard - Remove setting NAT as its already in PostUp/Down

[tremor021]

✍️ Description

🔗 Related PR / Discussion / Issue

Link: #2461

✅ Prerequisites

Before this PR can be reviewed, the following must be completed:

• [✅] Self-review performed – Code follows established patterns and conventions.
• [✅] Testing performed – Changes have been thoroughly tested and verified.

🛠️ Type of Change

Select all that apply:

• [✅] 🐞 Bug fix – Resolves an issue without breaking functionality.
• [] ✨ New feature – Adds new, non-breaking functionality.
• [] 💥 Breaking change – Alters existing functionality in a way that may require updates.
• [] 🆕 New script – A fully functional and tested script or script set.

📋 Additional Information (optional)