修理图片下载，增加消息中缺少的字段

clients/go_wcf_http/wcf/wcf.go

@@ -237,7 +237,7 @@ func (c *Client) RefreshPYQ() int32 {
 }
 
 // DecryptImage 解密图片 加密路径，解密路径
-func (c *Client) DecryptImage(src, dst string) int32 {
+func (c *Client) DecryptImage(src, dst string) string {
 	req := genFunReq(Functions_FUNC_DECRYPT_IMAGE)
 	q := Request_Dec{
 		Dec: &DecPath{Src: src, Dst: dst},
@@ -251,7 +251,8 @@ func (c *Client) DecryptImage(src, dst string) int32 {
 	if err != nil {
 		logs.Err(err)
 	}
-	return recv.GetStatus()
+
+	return recv.String()
 }
 
 // AddChatRoomMembers 添加群成员