(ITS#3811) test020 needs some log level

[ando@sys-net.it]

Full_Name: Pierangelo Masarati
Version: any?
OS: Linux (irrelevant)
URL: ftp://ftp.openldap.org/incoming/
Submission from: (NULL) (81.74.43.82)
Submitted by: ando


If test020 (proxy cache) is run with loglevel set to 0, it fails because it
inspects logs to check cacheability/answerability of queries.  Either the
appropriate log level is enforced when explicitly disabled by the user, or the
test is skipped when it cannot be performed correctly.

p.