[ISSUE-72] add missing attr (#80)

Author: Crim

kafka-webview-ui/src/main/java/org/sourcelab/kafka/webview/ui/controller/configuration/user/UserController.java

@@ -82,7 +82,8 @@ public String createUser(final UserForm userForm, final Model model) {
         // Setup breadcrumbs
         setupBreadCrumbs(model, "Create", "/configuration/user/create");
 
-        // Set user role options.
+        // Set isAdmin attribute
+        model.addAttribute("isAdmin", hasRole("ADMIN"));
         model.addAttribute("userRoles", getUserRoleOptions());
 
         return "configuration/user/create";