legacy c-ares binding should use legacy timer

lib/dns_legacy.js

@@ -26,7 +26,7 @@ var IOWatcher = process.binding('io_watcher').IOWatcher;
 
 var watchers = {};
 var activeWatchers = {};
-var Timer = process.binding('timer_wrap').Timer;
+var Timer = process.binding('timer').Timer;
 
 var timer = new Timer();