[ticket/13045] Remove Pragma headers

PHPBB3-13045

phpBB/install/index.php

@@ -446,7 +446,6 @@ class module
 		header('Content-type: text/html; charset=UTF-8');
 		header('Cache-Control: private, no-cache="set-cookie"');
 		header('Expires: ' . gmdate('D, d M Y H:i:s', time()) . ' GMT');
-		header('Pragma: no-cache');
 
 		return;
 	}