fixed time of default config loading

cbutil/upload.py

@@ -38,8 +38,8 @@ class DBConfig:
 
 
 class Uploader:
-    def __init__(self, config: DBConfig = load_config_from_env()):
-        self.config = config
+    def __init__(self, config: DBConfig = None):
+        self.config = config if config else load_config_from_env()
 
         self.client = InfluxDBClient(
             host=config.host,