fix send cookie

Author: ncode

templates/named.conf.erb

@@ -54,7 +54,7 @@ options {
 	min-refresh-time <%= @min_refresh_time %>;
 <%- end -%>
 <%- if @send_cookie -%>
-	send-cookie <%= @send_cookie ? 'true' : 'false' %>;
+	send-cookie <%= @send_cookie %>;
 <%- end -%>
 <%- if @max_retry_time -%>
 	max-retry-time <%= @max_retry_time %>;