AMBARI-12987. Edit button on Admin->kerberos page does not work. (jaimin)

ambari-web/app/controllers/main/admin/kerberos.js

@@ -466,7 +466,7 @@ App.MainAdminKerberosController = App.KerberosWizardStep4Controller.extend({
 
 
   makeConfigsEditable: function () {
-    if (!this.get('stepConfigs') || !this.get('stepConfigs.length')) {
+    if (this.get('stepConfigs') && this.get('stepConfigs.length')) {
       this.set('isEditMode', true);
       this.get('stepConfigs').forEach(function (_stepConfig) {
         _stepConfig.get('configs').setEach('isEditable', true);