message: docs: fix email cc typo
  Fixes To: field of security email templates
  Risk level: Low
  Testing: n/a
  Doc Changes: yes
  Release Notes: n/a
diff: @@ -28,7 +28,7 @@ $PERSON (on behalf of the Envoy maintainers)
  ```
  Subject: [CONFIDENTIAL] Further details on security release of Envoy $VERSION
  -To: envoy-announce@googlegroups.com
  +To: cncf-envoy-distributors-announce@lists.cncf.io
  Cc: envoy-security@googlegroups.com
  Hello Envoy Distributors,
  