Add Windows 10 NCSI response

[gaelmuller]

On Windows 10, the Network Connectivity Status Indicator is based on a request made to the following URL: http://www.msftconnecttest.com/connecttest.txt

This PR adds a valid response so that Windows 10 systems are considered connected to the Internet when using fakenet-ng.

[strictlymike]

Thank you for this contribution!

It seems reasonable to expect that this new file used by Windows 10 systems won't break FakeNet for Windows 7 or for Linux, so I'm open to fast-tracking this change without full regression testing.

In your branch, can you please bump up the minor version number in the three files referenced in our documentation for Developing for FakeNet-NG?

(Please also add a comment to the changelog similar to the ones already there, briefly describing the reason for the version change)