fix(traefik): Update traefik how to URL (#20029)

**Description**
In my brief search to figure out why the items on
https://truecharts.org/charts/description_list aren't listing the new
train names, I stumbled upon this bit of the traefik help text that had
a broken link. Seemed like an easy fix :)

**⚙️ Type of change**

- [ ] ⚙️ Feature/App addition
- [x] 🪛 Bugfix
- [ ] ⚠️ Breaking change (fix or feature that would cause existing
functionality to not work as expected)
- [ ] 🔃 Refactor of current code

**🧪 How Has This Been Tested?**
I tried navigating to
https://truecharts.org/charts/premium/traefik/how-to/ and it works!

**✔️ Checklist:**

- [x] ⚖️ My code follows the style guidelines of this project
- [x] 👀 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
- [ ] ⚠️ My changes generate no new warnings
- [ ] 🧪 I have added tests to this description that prove my fix is
effective or that my feature works
- [x] ⬆️ I increased versions for any altered app according to semantic
versioning
- [ ] I made sure the title starts with `feat(chart-name):`,
`fix(chart-name):` or `chore(chart-name):`

charts/premium/traefik/Chart.yaml

@@ -36,4 +36,4 @@ sources:
   - https://github.com/truecharts/charts/tree/master/charts/premium/traefik
   - https://github.com/truecharts/containers/tree/master/apps/traefik
 type: application
-version: 26.9.8
+version: 26.9.9

charts/premium/traefik/questions.yaml

@@ -414,7 +414,7 @@ questions:
   - variable: warning
     group: Documentation
     label: 'WARNING: If installed, be sure to move the TrueNAS GUI to another port (not 80 or 443).'
-    description: 'See: <br /><a href="https://truecharts.org/charts/enterprise/traefik/how-to">https://truecharts.org/charts/enterprise/traefik/how-to</a> for more info.'
+    description: 'See: <br /><a href="https://truecharts.org/charts/premium/traefik/how-to">https://truecharts.org/charts/premium/traefik/how-to</a> for more info.'
     schema:
       additional_attrs: true
       type: dict