C#: fix[support old version] fileType instead parsing
C#: fix[support old version] fileType instead parsing

ONLYOFFICE/document-server-integration,ONLYOFFICE/document-server-integration,ONLYOFFICE/document-server-integration,ONLYOFFICE/document-server-integration,ONLYOFFICE/document-server-integration,ONLYOFFICE/document-server-integration,ONLYOFFICE/document-server-integration,ONLYOFFICE/document-server-integration