Richmond school students will no longer be automatically expelled for first-time drug offenses. The school board voted 7-1 yesterday for a new code of conduct that gives principals and other administrators some discretion in dealing with students caught with drugs. It reflects a change in the Code of Virginia that goes into effect today, that modifies the state’s zero-tolerance policy. Until now, expulsion was recommended no matter what the circumstances. School districts now have the option of lesser penalties. Richmond school officials are currently reviewing several treatment and counseling options.