fix docker compose issue (#238)

### What problem does this PR solve?

_Briefly describe what this PR aims to solve. Include background context
that will help reviewers understand the purpose of the PR._

Issue link:#[[Link the issue
here](https://github.com/infiniflow/ragflow/issues/226)]

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

api/apps/document_app.py

@@ -65,6 +65,11 @@ def upload():
             DocumentService.query,
             name=file.filename,
             kb_id=kb.id)
+        filetype = filename_type(filename)
+        if not filetype:
+            return get_data_error_result(
+                retmsg="This type of file has not been supported yet!")
+
         location = filename
         while MINIO.obj_exist(kb_id, location):
             location += "_"