Partially revert "Update license for OpenStreetMap (#883)."

This reverts the parts of commit 350567f5
that are outside of the README and should not have been included.

lib/geocoder/lookups/base.rb

@@ -86,6 +86,15 @@ module Geocoder
         @cache
       end
 
+      ##
+      # Array containing the protocols supported by the api.
+      # Should be set to [:http] if only HTTP is supported
+      # or [:https] if only HTTPS is supported.
+      #
+      def supported_protocols
+        [:http, :https]
+      end
+
       private # -------------------------------------------------------------
 
       ##
@@ -99,7 +108,6 @@ module Geocoder
       # Object used to make HTTP requests.
       #
       def http_client
-        protocol = "http#{'s' if use_ssl?}"
         proxy_name = "#{protocol}_proxy"
         if proxy = configuration.send(proxy_name)
           proxy_url = !!(proxy =~ /^#{protocol}/) ? proxy : protocol + '://' + proxy
@@ -183,7 +191,7 @@ module Geocoder
           JSON.parse(data)
         end
       rescue => err
-        raise_error(ResponseParseError.new(data)) or Geocoder.log(:warn, "Geocoding API's response was not valid JSON.")
+        raise_error(ResponseParseError.new(data)) or Geocoder.log(:warn, "Geocoding API's response was not valid JSON: #{data}")
       end
 
       ##
@@ -265,6 +273,7 @@ module Geocoder
       def make_api_request(query)
         timeout(configuration.timeout) do
           uri = URI.parse(query_url(query))
+          Geocoder.log(:debug, "Geocoder: HTTP request being made for #{uri.to_s}")
           http_client.start(uri.host, uri.port, use_ssl: use_ssl?) do |client|
             req = Net::HTTP::Get.new(uri.request_uri, configuration.http_headers)
             if configuration.basic_auth[:user] and configuration.basic_auth[:password]
@@ -279,8 +288,14 @@ module Geocoder
       end
 
       def use_ssl?
+        if supported_protocols == [:https]
+          true
+        elsif supported_protocols == [:http]
+          false
+        else
           configuration.use_https
         end
+      end
 
       def check_api_key_configuration!(query)
         key_parts = query.lookup.required_api_key_parts