Don't warn about uncaged reserved users.
Don't warn about uncaged reserved users.

Case 189717: Some users starting with "cpanel", along with a variety of
other system users, were being listed as uncaged, even though that's
expected and desired.  Caging those users might cause the respective
software not to work properly.  Skip these reserved users when checking
as they do not represent a security risk.

sporks5000/addon_securityadvisor,edwbuck/addon_securityadvisor,bdraco/addon_securityadvisor