feat: add root config option for sftp connection in flysystem

config/packages/flysystem.yaml

@@ -9,6 +9,7 @@ flysystem:
                 port: '%env(int:SFTP_XML_EXPORT_PORT)%'
                 username: '%env(SFTP_XML_EXPORT_USER)%'
                 password: '%env(SFTP_XML_EXPORT_PASSWORD)%'
+                root: '%env(SFTP_XML_EXPORT_ROOT)%'
         xml_dump.storage:
             local:
                 directory: '%kernel.project_dir%/var/bpn'