Investigate GeoIP-based search results feature in ESR 38

https://bugzilla.mozilla.org/show_bug.cgi?id=1109120 implemented GeoIP-based search defaults including contacting https://location.services.mozilla.com. Moreover, on OS X and Windows OS APIs are used to get that information:

We should investigate possible information leaks and I guess ways to disable/neuter this feature as we ship Disconnect.me with en-US as default.