Greg Nishi­oka has resigned as administrator of the Honolulu Liquor Commission.  The agency met in executive session yesterday about Nishioka's employment and accepted his resignation, effective August 30.   Commission Chair Michael Yamaguchi issued a statement saying because it is a personnel matter, the Commission can't comment on the resignation at this time.  The Honolulu Star-Advertiser attributes information from the state Disciplinary Board of the Hawaii Supreme Court showing that in February, Nishioka resigned from practicing law and agreed to repay misappropriated money to clients.