Apply suggestion from code review

Author: RebeccaTamachiro

src/content/docs/ssl/edge-certificates/changing-dcv-method/methods/delegated-dcv.mdx

@@ -31,7 +31,7 @@ You should use Delegated DCV when all of the following conditions are true:
 - Cloudflare is not already [performing DCV automatically](/ssl/edge-certificates/changing-dcv-method/).
 - Your zone is using an [Advanced certificate](/ssl/edge-certificates/advanced-certificate-manager/).
 - Your zone is not using multiple CDN providers.
-- The Certificate Authority is either Google Trust Services, SSL.com or Let's Encrypt
+- The Certificate Authority is either Google Trust Services, SSL.com, or Let's Encrypt
 
 :::note[Delegated DCV and origin certificates]