Fix facebook counter url

[xdimedrolx]

REST API is deprecated for versions v2.1 and higher (12)

[sapegin]

Should we change the host again? See #184.

[xdimedrolx]

Yes, we should change url.
Rest api is now deprecated, no longer works.
e.g., for
https://api.facebook.com/restserver.php?format=json&method=links.getStats&urls=https://github.com
The result is:
{ error_code: 12, error_msg: "REST API is deprecated for versions v2.1 and higher (12)", request_args: [ { key: "format", value: "json" }, { key: "method", value: "links.getStats" }, { key: "urls", value: "https://github.com" } ] }

[sapegin]

Interesting. Version 2.1 of what? :-)

[gldmtr]

Version 2.1 of FB api. That was my bad. But I have not seen any info about rest-api deprecation.