reduce the loop number from 1000 to 100

because 200 seconds are enough for waiting for a dnode to start up and be ready. 200 seconds can make the case running time much shorter in case of dnode2 failure

tests/script/unique/big/maxvnodes.sim

@@ -52,7 +52,7 @@ $x = 0
 show3: 
 	$x = $x + 1
 	sleep 2000
-	if $x == 1000 then 
+	if $x == 100 then 
 		return -1
 	endi