[ticket/15342] Check if is resource before close it

PHPBB3-15342

phpBB/includes/acp/acp_database.php

@@ -187,7 +187,10 @@ class acp_database
 
 								$storage->write_stream($file, $fp);
 
-								fclose($fp);
+								if (is_resource($fp))
+								{
+									fclose($fp);
+								}
 
 								$storage->track_file($file);