auth: do not use cct unless i have to

auth: do not use cct unless i have to

crimson messenger's tests does not use ConfigProxy at the time of writing,
and ldout() cannot tell if a log message should be written to the
logfile or not without querying config subsystem, so, to avoid involving
config system in crimson messenger's tests, the log line is disabled if
WITH_SEASTAR, we will kill this workaround once we ditch crimson/net/Config.h.

Signed-off-by: Kefu Chai <kchai@redhat.com>