LegacyStorageFileRowReader: handle the case when statement->fetch ret…

…urns false (#89)

* LegacyStorageFileRowReader: handle the case when statement->fetch returns false

* Update eZ/Bundle/EzPublishIOBundle/Migration/FileLister/FileRowReader/LegacyStorageFileRowReader.php

Co-authored-by: Andrew Longosz <alongosz@users.noreply.github.com>

Co-authored-by: Andrew Longosz <alongosz@users.noreply.github.com>

eZ/Bundle/EzPublishIOBundle/Migration/FileLister/FileRowReader/LegacyStorageFileRowReader.php

@@ -42,7 +42,7 @@ final public function getRow()
     {
         $row = $this->statement->fetch();
 
-        return $this->prependMimeToPath($row['filename'], $row['mime_type']);
+        return false !== $row ? $this->prependMimeToPath($row['filename'], $row['mime_type']) : null;
     }
 
     final public function getCount()