update internet connection check to correctly identify SFTP backends

[kmwoley]

Add support to correctly check for internet access when using SFTP backends.

In the docs, we make it clear that the user should disable the internet connection checks if using SFTP.

Edit config.ps1 and turn off the internet connection test: $InternetTestAttempts = 0 as the test does not recognize sftp addresses correctly

It would be better if the script just handled this correctly.