fix discord link (thanks @louwers)

CODE_OF_CONDUCT.md

@@ -60,7 +60,7 @@ representative at an online or offline event.
 ## Enforcement
 
 Instances of abusive, harassing, or otherwise unacceptable behavior may be
-reported to the community leaders responsible for enforcement on [discord](discordapp.com/users/608636479765348381).
+reported to the community leaders responsible for enforcement on [discord](https://discordapp.com/users/608636479765348381).
 All complaints will be reviewed and investigated promptly and fairly.
 
 All community leaders are obligated to respect the privacy and security of the