update discord link

Author: 2hmad

.github/ISSUE_TEMPLATE/request-feature.yml

@@ -9,7 +9,7 @@ body:
  attributes:
  value: |
  ### Before you submit
- - Don't forget you can ask your questions in our [Discord server](https://gofiber.io/discord).
+ - Don't forget you can ask your questions in our [Discord server](https://discord.com/invite/JKcTwZYJ).
  - Write your issue clearly.
  - type: textarea
  id: description