Change copy on list header

app/views/projects/clusters/index.html.haml

@@ -7,7 +7,7 @@
   - else
     .top-area.adjust
       .nav-text
-        = s_("ClusterIntegration|Control your environments separately by adding multiple clusters to your project")
+        = s_("ClusterIntegration|Clusters can be used to deploy applications and to provide Review Apps for this project")
       .pull-right.nav-bar-right
         = link_to s_("ClusterIntegration|Add cluster"), new_project_cluster_path(@project), class: "btn btn-success disabled has-tooltip js-add-cluster", title: s_("ClusterIntegration|Multiple clusters are available in GitLab Entreprise Edition Premium and Ultimate")
     .ci-table.js-clusters-list