don't show graph if type is unset in definitions, eg os areca

git-svn-id: http://www.observium.org/svn/observer/trunk@3215 61d68cd4-352d-0410-923a-c4978735b2b8

html/includes/device-header.inc.php

@@ -53,6 +53,8 @@ echo('
 $graph_array['bg']     = "FFFFFF00";
 
 foreach ($graphs as $entry)
+{
+  if ($entry['graph'])
   {
     $graph_array['type']   = $entry['graph'];
 
@@ -61,6 +63,7 @@ echo('
     echo("<div style='font-weight: bold; font-size: 7pt; margin: -3px;'>".$entry['text']."</div>");
     echo("</div>");
   }
+}
 
 unset($graph_array);