Prepare 4.1.21 release

Author: lcharette

app/defines.php

@@ -3,7 +3,7 @@
 namespace UserFrosting;
 
 // Some standard defines
-define('UserFrosting\VERSION', '4.1.20');
+define('UserFrosting\VERSION', '4.1.21');
 define('UserFrosting\DS', '/');
 define('UserFrosting\PHP_MIN_VERSION', '5.6');
 define('UserFrosting\DEBUG_CONFIG', false);