Change shortcut creation path to reflect updated format

[Amras2322]

Changed one line, switching "Steam Art Manager.exe" to "app.exe" Missed it on my last pull request

Relates to #1248

• [x] I have read the Contributing Guide.

[github-actions[bot]]

All changes look good.

Wait for review from human collaborators.

steam-art-manager

• [x] Description
• [x] License
• [x] Hashes
• [x] Checkver
• [x] Autoupdate