regenerate jpeg encoder (#1198)

* regenerate jpeg encoder

* add README to gif/jpeg

* 开机启动显示开发板信息，提前启动event loop

main/system_info.h

@@ -13,6 +13,7 @@ public:
     static size_t GetFreeHeapSize();
     static std::string GetMacAddress();
     static std::string GetChipModelName();
+    static std::string GetUserAgent();
     static esp_err_t PrintTaskCpuUsage(TickType_t xTicksToWait);
     static void PrintTaskList();
     static void PrintHeapStats();