config.def.h: improve latency for the default configuration

config.def.h

@@ -53,7 +53,7 @@ int allowwindowops = 0;
  * near minlatency, but it waits longer for slow updates to avoid partial draw.
  * low minlatency will tear/flicker more, as it can "detect" idle too early.
  */
-static double minlatency = 8;
+static double minlatency = 2;
 static double maxlatency = 33;
 
 /*