Fix code to avoid callback usage (this fails on some php)

htdocs/index.php

@@ -407,10 +407,11 @@ $var=true;
 
 //Remove any invalid response
 //load_board can return an integer if failed or WorkboardResponse if OK
-$valid_dashboardlines = array_filter($dashboardlines, function ($board) {
-	return $board instanceof WorkboardResponse;
-});
-
+$valid_dashboardlines=array();
+foreach($dashboardlines as $tmp)
+{
+	if ($tmp instanceof WorkboardResponse) $valid_dashboardlines[] = $tmp;
+}
 $rowspan = count($valid_dashboardlines);
 
 foreach($valid_dashboardlines as $board)