add tmp buffer to store messages until the log file is ready

src/log.h

@@ -17,7 +17,10 @@ public:
     bool m_running = false;
     bool m_error = false;
     std::thread m_thread;
+    std::mutex m_mutex;
     BlockingQueue<std::string> m_mq;
+    // Store messages until the file is open
+    std::vector<std::string> m_tmp;
     CURL *curl = nullptr;
     CURLcode res;
     std::string readBuffer;