WI: I-90/39 Exit #171 complex

[rickmastfan67]

Seems this interchange setup has been reconfigured since we had added it to the site.

There is no longer an Exit #171C, as it's been renumbered as #171B.
171C -> 171B

https://goo.gl/maps/doQczDHauzgWTANCA

This would also effect I-39's labels, as it's along for the ride on I-90 here.
171C(90) -> 171B(90)