Fix PHP Fatal error "Method Icinga\File\Csv::__toString() must not throw an exception in /vagrant/test/php/library/Icinga/File/CsvTest.php on line 35"

library/Icinga/File/Csv.php

@@ -5,6 +5,7 @@
 namespace Icinga\File;
 
 use Icinga\Data\Browsable;
+use Exception;
 
 class Csv
 {
@@ -27,6 +28,7 @@ class Csv
 
     public function __toString()
     {
+        try {
             $first = true;
             $csv = '';
             foreach ($this->query->getQuery()->fetchAll() as $row) {
@@ -42,5 +44,8 @@ class Csv
             }
 
             return $csv;
+        } catch (Exception $e) {
+            return (string) $e;
+        }
     }
 }