Merge pull request #1715 from laf/rrdoptions

Updated rrdtool_update() to use new array format

includes/polling/unix-agent.inc.php

@@ -38,7 +38,11 @@ if ($device['os_group'] == 'unix') {
             rrdtool_create($agent_rrd, 'DS:time:GAUGE:600:0:U '.$config['rrd_rra']);
         }
 
-        rrdtool_update($agent_rrd, 'N:'.$agent_time);
+        $fields = array(
+            'time' => $agent_time,
+        );
+ 
+        rrdtool_update($agent_rrd, $fields);
         $graphs['agent'] = true;
 
         foreach (explode('<<<', $agent_raw) as $section) {