fix: check element property before clone

Author: ly525

front-end/h5/src/components/core/models/element.js

@@ -27,8 +27,8 @@ class Element {
      * 3. 为何需要 clone，因为会有 element.clone() 以及 page.clone()，
      *    element.pluginProps 和 elementcommonStyle 是引用类型，如果不做 deep_clone 可能会出现意外错误
      */
-    this.pluginProps = clone(ele.pluginProps) || this.getDefaultPluginProps(ele.editorConfig || {})
-    this.commonStyle = clone(ele.commonStyle) || this.getDefaultCommonStyle()
+    this.pluginProps = (typeof ele.pluginProps === 'object' && clone(ele.pluginProps)) || this.getDefaultPluginProps(ele.editorConfig || {})
+    this.commonStyle = (typeof ele.commonStyle === 'object' && clone(ele.commonStyle)) || this.getDefaultCommonStyle()
     this.events = []
   }