incorrectly set up http auth results in growing url

enable http auth in zabbix, but do not configure actual http auth. while logged out, click on 'login' button - that adds new stuff to the url every time the button is clicked

example url :

index.php?request=%2Ftrunk%2Findex.php%3Frequest%3D%252Ftrunk%252Findex.php%253Frequest%253D%25252Ftrunk%25252Findex.php%25253Frequest%25253D%2525252Ftrunk%2525252Fauthentication.php