- updated MAX-TOKEN according to openai document

- minior optimization of code style
- fixed issues `RuntimeError: fail to reduce message length`

metagpt/config2.py

@@ -92,7 +92,7 @@ class Config(CLIParams, YamlModel):
         """
         default_config_paths: List[Path] = [
             METAGPT_ROOT / "config/config2.yaml",
-            Path.home() / ".metagpt/config2.yaml",
+            CONFIG_ROOT / "config2.yaml",
         ]
 
         dicts = [dict(os.environ)]
@@ -134,4 +134,3 @@ def merge_dict(dicts: Iterable[Dict]) -> Dict:
     return result
 
 
-config = Config.default()