Fix button's command variable

package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "grapesjs",
-  "version": "0.12.50",
+  "version": "0.12.51",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {

package.json

@@ -1,7 +1,7 @@
 {
   "name": "grapesjs",
   "description": "Free and Open Source Web Builder Framework",
-  "version": "0.12.50",
+  "version": "0.12.51",
   "author": "Artur Arseniev",
   "license": "BSD-3-Clause",
   "homepage": "http://grapesjs.com",

src/panels/view/ButtonView.js

@@ -203,7 +203,7 @@ module.exports = Backbone.View.extend({
     const model = this.model;
     const context = model.get('context');
     const parent = this.parentM;
-    var command  = null;
+    let command = {};
     var editor = this.em && this.em.get ? this.em.get('Editor') : null;
     var commandName = model.get('command');
 
@@ -220,7 +220,7 @@ module.exports = Backbone.View.extend({
       model.set('active', true, { silent: true }).trigger('checkActive');
       parent && parent.set('active', true, { silent: true }).trigger('checkActive');
 
-      if (command && command.run) {
+      if (command.run) {
         command.run(editor, model, model.get('options'));
         editor.trigger('run:' + commandName);
       }
@@ -232,7 +232,7 @@ module.exports = Backbone.View.extend({
       model.collection.deactivateAll(context);
       parent && parent.set('active', false, { silent: true }).trigger('checkActive');
 
-      if (command && command.stop) {
+      if (command.stop) {
         command.stop(editor, model, model.get('options'));
         editor.trigger('stop:' + commandName);
       }