Bandwidth files in v3bw dir can't be read by a different user other than sbws user

Files inside v3bw have perimssions 600 and are owned by sbws user. Directory v3bw have permissions 700 and is owned by sbws user. The files in v3bw directory needs to be readable by either a tor or rsync users.

This issue was introduced by #40162 (closed) (pen-torproject#2)