Bug#4091 - Log "Operation not permitted" privs errors at NOTICE rather than
ERROR.
Reduce the scope of the logging changes to just those PRIVS calls related
to the effective (rather than the real) IDs.
Merge pull request #32 from proftpd/core-privs-error-logging-bug4091

Bug#4091 - Log "Operation not permitted" privs errors at NOTICE rather t...