fix: credential check valid in parser

bilibili_api/tools/parser/parser.py

@@ -36,7 +36,7 @@ async def __aenter__(self):
             obj, err = await self.parse(val)
             if err is None:
                 if isinstance(obj, bilibili_api.Credential):
-                    self.valid = await bilibili_api.check_valid(obj)
+                    self.valid = await obj.check_valid()
                 self.params[key] = obj
         return self