Fix malformed link

A link on this page had a stray period between the link text and the
link destination.

doc/user/project/pages/custom_domains_ssl_tls_certification/index.md

@@ -61,7 +61,7 @@ according to the type of domain you want to use with your Pages site:
 - [For both](#for-both-root-and-subdomains).
 
 NOTE: **Note:**
-You can [configure IPv6 on self-managed instances].(../../../../administration/pages/index.md#advanced-configuration),
+You can [configure IPv6 on self-managed instances](../../../../administration/pages/index.md#advanced-configuration),
 but IPv6 is not currently configured for Pages on GitLab.com.
 Follow [this issue](https://gitlab.com/gitlab-org/gitlab/-/issues/214718) for details.