KEYCLOAK-2203 - Add new cluster node form doesn't validate host input

forms/common-themes/src/main/resources/theme/base/admin/resources/partials/client-clustering-node.html

@@ -17,7 +17,7 @@
         <div class="form-group">
             <label class="col-md-2 control-label" for="host">Host</label>
             <div class="col-sm-6">
-                <input ng-disabled="!create" class="form-control" type="text" id="host" name="host" data-ng-model="node.host">
+                <input ng-disabled="!create" class="form-control" type="text" id="host" name="host" data-ng-model="node.host" required>
             </div>
         </div>
         <div class="form-group">