Redmine #6558: Fix LookupAccountName error message on Windows.

Don't report error for user name "root" on Windows, since it is not
expected to exist.

(cherry picked from commit fb72b05d47b8f5d08b8ac2c3c1b2ee8d4157062b)
Change: Fix laterthan test

The or() function returns a string, not a boolean.
https://docs.cfengine.com/latest/reference-functions-or.html

(cherry picked from commit 95e31650aa324b94287ffcc2ae5234f41c885f62)