update issue template

.github/ISSUE_TEMPLATE

@@ -17,28 +17,28 @@ Please read the [instruction](https://www.v2ray.com/en/get_started/issue.html) a
     Please attach your configuration file (**Mask IP addresses before submit this issue**).
 
     Server Configuration File（服务器端配置文件）:
-    ```javascript
+```javascript
     // 在这里附上服务器端配置文件
     // Please attach your server configuration file here.
-    ```
+```
 
     Client Configuration File（客户端配置文件）:
-    ```javascript
+```javascript
     // 在这里附上客户端配置文件
     // Please attach your client configuration file here.
-    ```
+```
 
 6)  请附上出错时软件输出的日志。在 Linux 中，日志通常在 `/var/log/v2ray/error.log` 文件中。
     Please attach the log file, especially the bottom lines if the file is large. Log file is usually `/var/log/v2ray/error.log` on Linux.
 
     Server Log File（服务器端日志）:
-    ```
+```
     // 在这里附上服务器端日志
     // Please attach your server log here.
-    ```
+```
 
     Client Log File（客户端日志）:
-    ```
+```
     // 在这里附上客户端日志
     // Please attach your client log here.
-    ```
+```