Add EE specific logic to Add Cluster button

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

@@ -9,7 +9,10 @@
       .nav-text
         = s_("ClusterIntegration|Clusters can be used to deploy applications and to provide Review Apps for this project")
       .nav-controls
-        = link_to s_("ClusterIntegration|Add cluster"), new_project_cluster_path(@project), class: "btn btn-success btn-add-cluster disabled has-tooltip js-add-cluster", title: s_("ClusterIntegration|Multiple clusters are available in GitLab Entreprise Edition Premium and Ultimate")
+        - if @project.feature_available?(:multiple_clusters)
+          = link_to s_("clusterintegration|add cluster"), new_project_cluster_path(@project), class: "btn btn-success btn-add-cluster has-tooltip js-add-cluster"
+        - else
+          = link_to s_("ClusterIntegration|Add cluster"), new_project_cluster_path(@project), class: "btn btn-success btn-add-cluster 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
       .gl-responsive-table-row.table-row-header{ role: "row" }
         .table-section.section-30{ role: "rowheader" }