LDEV-2803: Make SessionManager recreate SSO cookie after it has been deleted (revert to version before changes made for
LDEV-2771). Prevent SingleSignOn from deleting SSO cookies. It is required for Sysadmin "Login as" feature. For authentication from external servers using LoginRequestServlet, SSO cookied removal is needed (
LDEV-2719), but it is already done in Servlet class.