方法来自:http://bbs.csdn.net/topics/391851823 roby520的回答
亲测有效版本:4.1
把ckeditor/plugins/image/dialogs/image.js中的
this.imageElement.getAttribute("style") || this.imageElement.removeAttribute("style");
改为
this.imageElement.setAttribute("style")&&this.imageElement.removeAttribute("style");