Update README.md

README.md

@@ -51,7 +51,7 @@ http://192.168.x.x:8080 would show you what's running INSIDE the container on po
 * `-v /downloads` - torrent download directory
 * `-e PGID` for GroupID - see below for explanation
 * `-e PUID` for UserID - see below for explanation
-* `-e UMASK_SET` for umask setting of deluge, umask_variable , default if left unset is 022. 
+* `-e UMASK_SET` for umask setting of deluge, *optional* , default if left unset is 022. 
 * `-e TZ` for timezone information, eg Europe/London
 
 It is based on alpine linux with s6 overlay, for shell access whilst the container is running do `docker exec -it deluge /bin/bash`.