Log errors in Logger-compatible way

Fixes #17

Author: mperham

lib/async/dns/handler.rb

@@ -59,7 +59,7 @@ def process_query(data, options)
 
 				return @server.process_query(query, options)
 			rescue StandardError => error
-				@logger.error(self, error)
+				@logger.error(self) { error }
 
 				return error_response(query)
 			end