enhance: when setting the log output file, stellar still outputs necessary log information to stderr

src/log/log.cpp

@@ -321,5 +321,11 @@ void log_print(enum log_level level, const char *module, const char *fmt, ...)
         {
             nwrite = write(g_log_ctx->log_fd, buf, p - buf);
         } while (nwrite == -1 && errno == EINTR);
+
+        // log level is LOG_STATE, also print to stderr
+        if (level == LOG_STATE)
+        {
+            fprintf(stderr, "%s", buf);
+        }
     }
 }