Can't log in if double slash was in the URL

Login doesn't work, if the url was with a double slash and then with one slash
Steps to reproduce:

1. Enter url in the browser address bar as "http://localhost/4.0//"
2. Log in as Admin
3. Enter url in address bar as "http://localhost/4.0"
4. Log out
5. Try to log in as Admin

Result: Logged in as guest with message on dashboard "Session terminated, re-login, please.". Created two zbx_sessions, for path /4.0 and for /4.0/
Expected: Login successful