webfinger: use https as default fallback instead of http

realistically, all instances need to be on https anyway to properly federate with all
software

lib/pleroma/web/web_finger/web_finger.ex

@@ -253,7 +253,7 @@ defmodule Pleroma.Web.WebFinger do
           String.replace(template, "{uri}", URI.encode(account))
 
         _ ->
-          "http://#{domain}/.well-known/webfinger?resource=acct:#{account}"
+          "https://#{domain}/.well-known/webfinger?resource=acct:#{account}"
       end
 
     with response <-