Doesn't log if user is not in a subsystems

[evsinev]

How to reproduce it:

1. Create subsystem SUBSYSTEM_1
2. Create user USER_1
3. Do not append USER_1 to SUBSYSTEM_1
4. Login as USER_1 to SUBSYSTEM_1
5. superfly shows error: "Can't login to SUBSYSTEM_1"
6. There are no any log messages in the log4j output for this. We expected the warn message from the SSOUtils.redirectToCantLoginErrorPage(...) method