避免错误

src/UI/Components/MainContent/Login.tsx

@@ -43,7 +43,7 @@ export default class Login extends React.Component<{ store?: TopPanelStore; }, I
     {
         super(props);
         this.state = {
-            user_name: localStorage.getItem(StoreageKeys.UserName),
+            user_name: localStorage.getItem(StoreageKeys.UserName) ?? "",
             pass_word: "",
         };
     }