added more information on running composer update when upgrading to 4.1

I had a different outcome when upgrading on a different server (shared hosting). I thought to share how I was able to circumvent that issue. Apparently, `composer update --no-scripts` doesn't always work. Though, running `composer update --no-scripts` did the trick on my local server at home.

Ravi.
that note about linux is wrong too. You just need to set the correct file permissions.