fix #2232: set rulename for default accept

fix #2232: set rulename for default accept

Logging the rulename along with the action taken introduced in
365d5b9549d25a910c82cd37034f05e1c906565a, introduced a regression, for the
default action (accept), since the accept-rule is instantiated directly it
did not set a name, resulting in an 'Use of uninitialized value' being written
to the mail.log for every mail not triggering any explicit rule.

Signed-off-by: Stoiko Ivanov <s.ivanov@proxmox.com>