Map hostnames returned from modules service supporting HTTPS

This is required as Google is no longer issuing SSL certificates for
double-wildcard domains hosted at appspot.com (i.e. *.*.appspot.com).

This is a breaking change as it is returning different values.

BUG=https://github.com/dart-lang/appengine/issues/9
R=kustermann@google.com

Review URL: https://codereview.chromium.org//758573002