avoid multiple paralell update checks

we now touch the messages before the actual update happens. this should
lower the chance of more than one update check running at a time.

inc/infoutils.php

@@ -25,12 +25,12 @@ function checkUpdateMessages(){
 
     // check if new messages needs to be fetched
     if($lm < time()-(60*60*24) || $lm < @filemtime(DOKU_INC.DOKU_SCRIPT)){
+        @touch($cf);
         dbglog("checkUpdatesMessages(): downloading messages.txt");
         $http = new DokuHTTPClient();
-        $http->timeout = 8;
+        $http->timeout = 12;
         $data = $http->get(DOKU_MESSAGEURL.$updateVersion);
         io_saveFile($cf,$data);
-        @touch($cf);
     }else{
         dbglog("checkUpdatesMessages(): messages.txt up to date");
         $data = io_readFile($cf);