login.defs.erb: set LOG_OK_LOGINS = "no", correct ENV_PATH syntax

LOG_OK_LOGINS is set to "no" by default in Debian which appears to be the upstream source of this template. All values should be default unless they can be configured by the module.

Add separator for ENV_PATH otherwise the first value in "additional_user_paths" will not be separated from the default value in the file.