Fix Sophos FIrewall article on extracting logs

This page https://support.sophos.com/support/s/article/KB-000035842?language=en_US no longer works. you cannot browse and copy logs using that script. you need to go into the advanced shell (select option 5. Device Management and 3. Advanced Shell. )

it worked on earlier versions of SFOS, but needs an update to still really be useful.