Error 500 appears if "SPRING_SECURITY_REMEMBER_ME_COOKIE" is empty and new "_ga" cookie is set

Pre-conditions:
Install plugin for editing cookies for your browser.
I.e. "EditThisCookie" for Chrome or "Cookies Manager+" for Mozilla Firefox

Steps:
1. Open javatalks.ru
2. Delete cookie with name "_ga" for domain .javatalks.ru
3. Delete cookie with name "SPRING_SECURITY_REMEMBER_ME_COOKIE" for domain javatalks.ru if it exists
3. Create new cookie with next data:

Name: SPRING_SECURITY_REMEMBER_ME_COOKIE
Domain: javatalks.ru
Path: /
Secure: No
Http only: No
Expiration: Session
Leave "Value" empty

4. Reload page 2 times

Actual result: Page with error "HTTP Status 500" is displayed (see screenshot in attachment)
Expected result: Main page of javatalks.ru is displayed

Note: Couldn't reproduce bug at testing instance, because it doesn't set "_ga" cookie.