[HTTPS-E Rulesets] Microsoft: handle i.s-microsoft.com as is

[Christopher Liu]

To whom it my concern:

It appears that i.s-microsoft.com now has a valid cert (i.e.,
correctly configured Akamai Edgekey) and no longer needs to be
rewritten to www.microsoft.com.

For example of use, see the www.microsoft.com homepage.

C. Liu