Merge branch 'fix-requirements' into 'master'

Docs: Fix zero downtime link in requirements

See merge request gitlab-org/gitlab-ce!23170

doc/install/requirements.md

@@ -104,7 +104,7 @@ features of GitLab work with MySQL/MariaDB:
 1. MySQL support for subgroups was [dropped with GitLab 9.3][post].
    See [issue #30472][30472] for more information.
 1. Geo does [not support MySQL](https://docs.gitlab.com/ee/administration/geo/replication/database.html#mysql-replication). This means no supported Disaster Recovery solution if using MySQL. **[PREMIUM ONLY]**
-1. [Zero downtime migrations][../update/README.md#upgrading-without-downtime] do not work with MySQL.
+1. [Zero downtime migrations](../update/README.md#upgrading-without-downtime) do not work with MySQL.
 1. GitLab [optimizes the loading of dashboard events](https://gitlab.com/gitlab-org/gitlab-ce/issues/31806) using [PostgreSQL LATERAL JOINs](https://blog.heapanalytics.com/postgresqls-powerful-new-join-type-lateral/).
 1. In general, SQL optimized for PostgreSQL may run much slower in MySQL due to
    differences in query planners. For example, subqueries that work well in PostgreSQL