partially revert #1559

Instead of automatically adding custom templates, we log an error if
that template is missing in the available templates. Still mitigates
arbitrary file inclusion, as the string is now checked against a fixed
allow list.

tst/Bootstrap.php

@@ -6,7 +6,9 @@ use Google\Cloud\Storage\Bucket;
 use Google\Cloud\Storage\Connection\ConnectionInterface;
 use Google\Cloud\Storage\StorageClient;
 use Google\Cloud\Storage\StorageObject;
+use PrivateBin\Configuration;
 use PrivateBin\Persistence\ServerSalt;
+use PrivateBin\TemplateSwitcher;
 
 error_reporting(E_ALL | E_STRICT);
 
@@ -26,6 +28,7 @@ if (!defined('CONF_SAMPLE')) {
 
 require PATH . 'vendor/autoload.php';
 Helper::updateSubresourceIntegrity();
+TemplateSwitcher::setAvailableTemplates(Configuration::getDefaults()['main']['availabletemplates']);
 
 /**
  * Class Helper provides unit tests pastes and comments of various formats