Update CVE-2017-17790.yml to remove old link

Removed outdated GitHub advisory link.

Author: jasnow

rubies/ruby/CVE-2017-17790.yml

@@ -33,5 +33,4 @@ related:
     - https://lists.debian.org/debian-lts-announce/2017/12/msg00025.html
     - https://lists.debian.org/debian-lts-announce/2018/07/msg00012.html
     - https://www.debian.org/security/2018/dsa-4259
-    - https://github.com/advisories/GHSA-qf67-vmxx-gp4j
     - https://github.com/advisories/GHSA-47cm-jxff-w8wg