fix bugs

src/MESA_handle_logger.c

@@ -149,6 +149,7 @@ int MESA_read_runtime_log_handle_conf(void* handle, const char* conf_file_path){
         return -1;
     }        
     struct runtime_log_handle* handle1 = (struct runtime_log_handle*)handle;
+    delete(handle1->conf);
     el::Configurations* conf = new el::Configurations(conf_file_path);
     handle1->conf = conf;
     el::Loggers::reconfigureLogger(handle1->logger, *(handle1->conf));