fix

docutranslate/converter/x2md/interfaces.py

@@ -1,5 +1,3 @@
-from typing import runtime_checkable
-
 from typing import Protocol
 from docutranslate.converter.interfaces import Converter
 from docutranslate.ir.document import Document
@@ -7,7 +5,6 @@ from docutranslate.ir.markdown_document import MarkdownDocument
 
 
 
-@runtime_checkable
 class X2MarkdownConverter(Converter,Protocol):
     """
     负责将其它格式的文件转换为markdown