_content/security/vuln: update link in index.md

Change-Id: I6c518332ccc15ddde797d2cb6d1c07cc08383876
Reviewed-on: https://go-review.googlesource.com/c/website/+/427597
Reviewed-by: Julie Qiu <julieqiu@google.com>
Reviewed-by: Brandon Kessler <bkessler@google.com>

_content/security/vuln/index.md

@@ -150,5 +150,5 @@ A good description can break down what an issue is,
 how it can be triggered, and what consumers should consider when determining
 the impact on their own software.
 
-Feel free to [file an issue](/s/govulncheck-feedback)
+Feel free to [file an issue](/s/vuln-feedback)
 if you would like to share your thoughts with us on this topic.