openbsdrcctl: extend enabled() to check flags

On OpenBSD, it's possible to define particular flags a daemon should be
enabled with (ala /etc/sysconfig/... in RedHat). To make sure the flags
are properly updated when changed (in pillars or states), we return a
service as "disabled" if the currently configured flags do not match the
provided ones; this ensures /etc/rc.conf.local is always in sync.