Gov. George Deukmejian has urged Californians to spend their vacation money here. In his weekly radio address, Deukmejian praised the state's new $5-million tourist advertising campaign, designed to promote California vacations via TV and magazine ads. The governor said the campaign's first objective is to "remind Californians that we have the world's greatest vacation destinations here in our own backyard." Deukmejian said that tourists spend $31 billion a year in California but that until the campaign began last year, the state had not used advertising to bolster the tourist trade.