Merge pull request #68 from phpList/phplist4

Add support for phpList4

Author: Sam Tuke

index.php

@@ -173,6 +173,7 @@ function checkRequiredFiles()
             'lt.php' => 1,
             'ut.php' => 1,
             'updater'=>1,
+            'base'=>1,
         );
 
         $existingFiles = scandir(__DIR__ . '/../');