timers: use start instead of stop + start

Instead of calling stop + start from the refresh method
of Timeout, instead just call start as libuv already
calls stop if necessary.

lib/internal/timers.js

@@ -85,7 +85,6 @@ Timeout.prototype[refreshFnSymbol] = function refresh() {
     // Would be more ideal with uv_timer_again(), however that API does not
     // cause libuv's sorted timers data structure (a binary heap at the time
     // of writing) to re-sort itself. This causes ordering inconsistencies.
-    this._handle.stop();
     this._handle.start(this._idleTimeout);
   } else if (this[unrefedSymbol]) {
     getTimers()._unrefActive(this);