Cache time on client as well

- Fixes FPS for me after suspend from 40 to 500 fps
- Should generally improve performance
- Might lead to a few problems where we need to call set_new_tick() in a
  few more positions, so test please

src/engine/client/client.cpp

@@ -2285,6 +2285,7 @@ void DemoPlayer()->SetPause(int paused)
 
 void CClient::Update()
 {
+	set_new_tick();
 	if(State() == IClient::STATE_DEMOPLAYBACK)
 	{
 		m_DemoPlayer.Update();