Adds 'logout' and 'register' to login redirect whitelist

app/includes/constants.php

@@ -1,5 +1,5 @@
 <?php
 // Pages that should not be used as redirect targets
 const INVALID_REDIRECT_PAGES = [
-    '', 'login', 'dashboard', '/'
+    '', 'login', 'logout', 'register', 'dashboard', '/'
 ];