Set default_url_options for action_mailer

This saves having to repeat the same host and protocol options
throughout the notifiers

config/application.rb

@@ -43,5 +43,8 @@ module OpenStreetMap
       config.logstasher.logger_path = LOGSTASH_PATH
       config.logstasher.log_controller_parameters = true
     end
+
+    # Set the host and protocol for all action mailer urls
+    config.action_mailer.default_url_options = { :host => SERVER_URL, :protocol => SERVER_PROTOCOL }
   end
 end