fix parser for pptx of which files are from filemanager (#2482)

### What problem does this PR solve?

#2467

### Type of change

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

api/apps/file2document_app.py

@@ -77,7 +77,7 @@ def convert():
                     doc = DocumentService.insert({
                         "id": get_uuid(),
                         "kb_id": kb.id,
-                        "parser_id": kb.parser_id,
+                        "parser_id": FileService.get_parser(file.type, file.name, kb.parser_id),
                         "parser_config": kb.parser_config,
                         "created_by": current_user.id,
                         "type": file.type,
@@ -85,7 +85,6 @@ def convert():
                         "location": file.location,
                         "size": file.size
                     })
-                    FileService.set_constant_parser(doc, file.name)
                     file2document = File2DocumentService.insert({
                         "id": get_uuid(),
                         "file_id": id,