Fix reuse of captions during send msg with file (#4500)

telethon/client/messages.py

@@ -826,6 +826,9 @@ class MessageMethods:
                 await client.send_message(chat, 'Hi, future!', schedule=timedelta(minutes=5))
         """
         if file is not None:
+            if isinstance(message, types.Message):
+                formatting_entities = formatting_entities or message.entities
+                message = message.message
             return await self.send_file(
                 entity, file, caption=message, reply_to=reply_to,
                 attributes=attributes, parse_mode=parse_mode,