remove extra label from logging print

Author: smokytheangel0

src/middleware/log_request.rs

@@ -40,7 +40,7 @@ impl Handler for LogRequests {
             "at={level} method={method} path=\"{path}\" \
              request_id={request_id} fwd=\"{ip}\" service={time_ms}ms \
              status={status} user_agent=\"{user_agent}\"\
-             metadata_length={metadata_length}",
+             {metadata_length}",
             level = level,
             method = req.method(),
             path = FullPath(req),