Merge branch 'docs-deployment-boards-in-user-group-clusters-docs' into 'master'

Fix a wrong link on group-level cluster doc page

See merge request gitlab-org/gitlab-ce!25693

Author: eread

doc/user/group/clusters/index.md

@@ -133,4 +133,4 @@ The following features are not currently available for group-level clusters:
 
 1. Terminals (see [related issue](https://gitlab.com/gitlab-org/gitlab-ce/issues/55487)).
 1. Pod logs (see [related issue](https://gitlab.com/gitlab-org/gitlab-ce/issues/55488)).
-1. Deployment boards (see [related issue](https://gitlab.com/gitlab-org/gitlab-ce/issues/55488)).
+1. Deployment boards (see [related issue](https://gitlab.com/gitlab-org/gitlab-ce/issues/55489)).