fix: logger formater is not work (infiniflow#1090)

### What problem does this PR solve?

as title

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

api/utils/log_utils.py

@@ -154,6 +154,11 @@ def get_handler(class_name, level=None, log_dir=None,
                                                delay=True)
         if level:
             handler.level = level
+        else:
+            handler.level = LoggerFactory.LEVEL
+
+        formatter = logging.Formatter(LoggerFactory.LOG_FORMAT)
+        handler.setFormatter(formatter)
 
         return handler